I was happy with an old van some years ago, until one day it lost an argument with a cup of sugar in the fuel tank (a very long story).
That you’re happy with any particular kernel is irrelevant, when the suggestion was to test others, which might have helped ascertain whether or not your issue is limited to kernel 6.12 on your hardware.
However, if you’re unwilling to investigate further, I’ll simply wish you luck and leave you with the following information, plus the usual request to provide system information as described (below).
Regards.
Welcome to the Manjaro community
As a new or infrequent forum user, please take some time to familiarise yourself with Forum requirements, and the many ways to use the forum to your benefit:
Update Announcements
The Update Announcements contain important information and a Known Issues and Solutions section that should generally be checked before posting a request for support.
System Information
While information from *-fetch type apps might be fine for someone wishing to buy your computer, for Support purposes it’s better to ask your system directly; 
Output of the inxi command with appropriate parameters will achieve this (naturally, formatted according to forum guidelines) and will generally be more useful for those wishing to help:
inxi --filter --verbosity=8
or the short form:
inxi -zv8
- inxi man pages (Arch Manual)
Be prepared to provide output from other commands whenever asked. It’s equally important to provide as much actionable information as possible in your first post, rather than simply indicating there is a problem.