I switched off all devices on the router and tried to find it without success.
it worked with another computer.
I also feel like it's a network problem.
What do you mean that it works on another computer?
If you can access it on another computer not from your PC the culprit is your PC and maybe you are using a VPN or something preventing you from accessing the miner's IP.
I can no longer get the miner to run with BraiinOs.
Unfortunately, I have difficulties to change the firmware, as no other firmware can be found up to now
Check this section "
Mining software (miners)" for other custom firmware. You can flash them through an SD card and it seems asic.to have firmware for this unit.