[Solved] Occupied memory in Xiaomi Redmi 7A - The system and the 'Other' category are filling up the

Hello,
For a long time now (it`s hard to say exactly, but it`s been 2-3, maximum 4 months) in my phone, I`ve been getting a message saying that there`s little memory left in the phone and I need to delete something. When I go to the settings to see the amount of memory, it shows that I have 14.8GB/16GB occupied (at the moment), most of which is taken up by "System", 6.17GB, and "Other", 6.56GB. Each time the message appears, I see a similar amount of space used. The remaining categories, such as "Photos", "Documents", "Applications", etc. occupy a total of about 2.5 GB. The strangest of these categories for me is the "Other" one, because not only is it the only one that doesn`t have an arrow next to it that would allow you to see what`s in it, but cleaning the phone with the built-in "Cleaner" or even "CCleaner" doesn`t do much at all big difference, and if they do, they are really small amounts, from 3 to 10MB.
As for the message itself and at what time intervals it appears, there is no specific rule for it. Sometimes it will appear once a week, sometimes once every 2-3 days, and sometimes even twice a day (I know that if I didn`t delete anything, it will appear as many times as I turn on the phone, so of course I`m talking about it here about its appearance between clearing the memory of garbage and other unnecessary things). Additionally, no matter what I do, no matter how many times I clear the phone`s memory or transfer some of the photos to my computer/Google drive/memory card or pendrive, this message will eventually come back.

My phone is, as I wrote in the headline: Xiaomi Redmi 7A
Model: M1903C3EG
Total memory: 16GB
RAM: 2GB
MIUI Version: MIUI Global 12.5.1 | Stable 12.5.1.0(QCMEUXM)
Android version: 10 QKQ1.191014.001
(if any information is missing, I apologize in advance and as soon as I find out what exactly is missing, I will add it)

I tried to look for ways to deal with it on the Internet, but I didn`t find anything that would help me. On my own, as I mentioned above, I also tried to simply delete files, transfer photos/videos/documents to a computer and other devices, but it didn`t help. I read somewhere about the trash bin in the gallery, but I also emptied it and nothing improved. Even before Christmas, at the beginning of my struggles with this problem, I restored the phone to factory settings, but even that did not bring any significant results (I transferred files such as photos, videos, etc. to the computer for that time, and after restoring factory settings, they came back on the phone). I also downloaded CCleaner and cleaned it with it, and today I also looked for "Storage Analyzer" in the Play Store and used it, but unfortunately I didn`t see much here either, because the files that appeared there had a total weight of about 250MB.

Is there any other method that would help me solve this problem? Can I do anything on my own, or should I take my phone to a service center and have someone more knowledgeable take care of it? Or maybe this type of phone already has this and I just have to bother with it until I buy a new one?
I don`t know what to do anymore, so I`m asking for some help.
Thank you in advance for any replies.

You can uninstall unnecessary applications. Some phone games can take up a lot of space.
You can always copy everything you need - photos, mp3, contacts or whatever else you need - and reset your phone to factory settings by deleting the files.

You do everything at your own risk

blekis wrote:

You can uninstall unnecessary applications. Some phone games can take up a lot of space.
You can always copy everything you need - photos, mp3, contacts or whatever else you need - and reset your phone to factory settings by deleting the files.

You do everything at your own risk

Except I don`t have any games installed. The only applications available on the phone are Facebook, Messenger, Whatsapp, Document Scanner, PeoPay (banking app), MojeIKP, o2 mail and Yanosik. I use all of them, so I can`t delete them. As for resetting the settings, I already wrote that I did that. I transferred everything I needed to my computer, reset the phone to factory settings, and then transferred the files from the computer back to the phone. From what I remember, about 1 week passed before the notification showed up again, and then it was still the same.

Facebook, massanger, whatsup. Janosik. This is where I think memory disappears. These apps eat up memory. Actually, I have Xiaomi 11, but the other folder takes up almost 10 GB, and the system is 14 GB, so it`s probably normal. I guess you can load a memory card into it. And that`s what I would recommend to you. If I`m wrong, I`m sorry. Unfortunately, 16GB is not enough these days. Unless you don`t use anything on your phone.

@winmap Are you sure it`s these apps` fault? I checked on another phone (Xiaomi Redmi 7, but with 32GB of memory, not 16GB like mine), where there were many more applications than mine and also a few games, the space occupied by "Other" was almost half less than mine, about 3.80GB (unless there was something different in this phone than in mine, because there was an additional category "Cached data" which also took up over 3GB, which is not available in my phone ).
As for the card, I already have one inserted, 32GB, but it doesn`t seem to help much, because despite saving everything possible on it, the notification about the used memory will eventually appear.

However, if it is indeed the fault of these few applications, is there any way to effectively get rid of some of their files in the "Other" category without causing the application to stop working? Or at least clean these files of garbage or reduce their size so that they take up e.g. half, or at least 3/4 of what they do now?

Lack of memory is a problem of older phones, the threads were discussed on the forum - you can read Link
As for the question, you can try to root the device, but this is also a short-term solution.

I think a memory card will be the best way. Although not all applications can be installed on it. You can do as the guy above wrote. It would probably be best to change your phone.

Well... If there`s no other option, I`ll play around with moving everything to my computer every now and then until I buy a new phone. Thank you all for your help.