[Solved] Circle IDOL toilet frame - sometimes flushes the cistern after draining water

Hello,
2 years ago installed flush frame. Once a week after draining, the water leaks into the toilet bowl (the drain valve does not close).
Then I drain the water a few times and "surprises" - it stops pouring.
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Access is quite difficult for the tank. I wonder if it could damage the drain valve or maybe there is another reason (embedded stone and therefore increased friction). Be what is only 2 years.
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Maybe someone has experience with this type of frame and valves.

Technical data:
Frame Wheel IDOL 99067
Drain valve 3/6 L - 32454307
I determined that the trigger switch is made by Siamp Monaco and has the same code, i.e. 32454307.

I am asking for some tips on how to diagnose the problem and what to do.
Bogdan



Added after 44 [seconds]:

The pictures show the frame before buildings and the construction of the drain valve itself.

Thank you for the suggestions.

For me it is as if the end was not coming back "piston" - the one ended with a gasket at the end - or pearly. Do this once a week, so once for dozens of water drains. Pressing the 6L button then solves the problem. Pressing 3L does not solve.

If it was still raining, I would actually put on a gasket. I have now extended the pushers so that there is no gap between the pushbutton and the pusher to count on being "deeper". Maybe the pusher bolts coincided with time (the thread is plastic and has a big jump).

I read on the internet that such a defect was observed on these racks, that from time to time the water was pouring. It may be a matter of adjusting the pusher setting (and consequently, the lever that pulls the bar visible on the photo)

Added after 56 [minutes]:

I bought a new valve and looked at how it works. It seems that it is possible to block the return of the "piston" when we lower the 3L and the float does not fall down and support the plunger. Maybe in the case of shallow pressure, this happens. The 6L pull in another way floats - for other protruding "teeth" and here I did not notice the possibility of blocking depending on the depth of insertion and the speed of sinking the float.

So for now it remains with the increase of "push" and then the idea of changing the position of the float. It looks like this valve requires subtle adjustments

Then I adjusted the distance between the button and the float