Archer C7 V5 - The 5Ghz problems are still there

Hi everyone, lately 5Ghz has been giving me a lot of problems. As shown in the image, I have 5Ghz which is disabled and there is no way to re-enable it. Two days ago I replaced the drivers ( build / 55251/3) because they gave me problems and the current ones were fine until today. So originally there were the:

  1. kmod-ath10k-ct
  2. ath10k-firmware-qca988x-ct

and I put:

  1. kmod-ath10k-ct
  2. ath10k-firmware-qca988x-ct

The latter ran for two days with an increase in bandwidth compared to the former but now it no longer works. The router is a Tp-Link Archer C7.

Now I re-installed the "ct" and the 5Ghz restarted for a few seconds then trying to change the channels it was disabled again and to re-enable it I had to restart the router. Furthermore, with the original drivers the channels beyond 64 do not go and setting them prorpio risks seeing the driver disabled. The countru code is set correctly. Any ideas on why?

I saw a version of drivers called "small buffer" but my router has 128mb of ram and half is empty. Does it make sense to try them? Why can't this problem found by other users be solved? Is there a possibility to reload the original firmware without risking bricking the router?
this is for test if it's a hardware problem.

Have you configured the correct country?
Have you set channel to fixed and within country limits?

Yes I have looked at it and it is correct. Also because if it were wrong the Country or the channel would not appear. In this case, however, it connects and then fails to connect. I forgot to put the screenshots. I put them on now.