Replacing Failed Seagate Barracuda 1.5TB in RAID1 with WD Red 3TB: Degraded, Rebuild & OK Status

A few days ago 1 of 2 identical drives (Seagate Barracuda 1.5 tb, 5900 rpm, 64mb cache) working in RAID 1 started catching bad sectors. Due to this, the system started to behave unstably, so I bought it in a nearby store (WD Red 3 tb, 5400 rpm, 64mb cache) to replace the damaged Seagate. Before I made the substitution, the matrix was going through different states.

First it was degraded, after the first reboot as below.

Then, after rebooting, there was a rebuild - information from Windows in the HWInfo program.
After a few hours of rebuilding the status OK - let me remind you that all this is still happening on both Seagate, I did not have WD purchased at that time. The state of the Member disk on both disks lasted, of course, until the disk was replaced with WD - I decided to replace the disk because the disk was catching more and more bad sectors and in a moment the rebuilding situation would repeat itself.
Currently, the status of the array is degraded, with the Seagate working disk being Member disk, and WD being Non-RAID disk status.

I wonder how can I connect this replaced drive to the array so that the data is synchronized to it with the Seagate drive currently operating in the array. Of course, the condition is that the data cannot be deleted, in the end I have a backup, but the point is, of course, that downtime is very much not recommended in the company.
I have nothing to manage this matrix under Windows Server 2012 R2, I can only manage it, as you can see in the screenshot, only during the restart by entering the matrix settings.

Pre-failure disk management below.

Below, disk management after replacing it with WD - unallocated is the new WD.

If the "falling" disk is still working, you can clone it (sectoral copy) to a new one or:
https://www.intel.pl/content/www/pl/pl/support/articles/000005775/technologies.html

I strongly suggest replacing the second drive as well. If you give both larger, you can extend the matrix:
https://www.intel.com/content/www/us/en/suppo...intel-rapid-storage-technology-intel-rst.html

Before I wrote here, I checked if it can be done in IRST, unfortunately the Intel Rapid Storage Technology software does not have such options as rebuilding to another disk, I will say more, it has no options, you can only read data about arrays, etc.
There is no other method to force a rebuild on a new disk?
The question is why the controller does not propose this itself, probably because the disk is larger, from another manufacturer, something else?

First you need to initialize / add the disk to the existing array, without it it won't propose to rebuild. You can probably do this from the IMSM option ROM. I do not know IRST, because this solution has no significant advantage on the software RAID, implemented at the operating system level ...

I will ask out of curiosity:
Is RAID1 Rebuild Not Automatic? I thought that this is how it works: I take out the damaged one, put a new one, add the disk to the array in the BIOS and after restart I have rebuilt the system and I can remove the second old disk ..........

It happens automatically, you just need to add a disk to the array.