Firmware 21.0+ changes ABI and causes issues with Homebrew that hasnt been updated past November 10 2025.
make copy of NRO then try putting your NRO into LibNX ABI Patcher.
If it doesnt break app or causes instability should be alright.
If you havent popped your Fuses (updating by Nintendo’s official servers) and updated manually, you can downgrade,
Like mines 20.4 firmware but i can drop lower as manually updated.
Edit: Apparently its updated to new ABi so try downgrading instead and see if fixes it or make sure you have updated pre-release 2