I'm sure Gigabyte will get around to fixing it at some point...
I'm quite happy with how my system is running at this point, but want to see if I could tweak my RAM timings just a smidgen more, but alas...
What Gigabyte board? I was messing around with a B450 Aorus M and a 3600 the other day and getting into a real mess using the DRAM calculator. It was Corsair LPX with Samsung B-die so failing to hit 3600 C14 was quite unexpected, really. 3600 CL14 on B-die is pretty much guaranteed with even garbage-tier boards.
I read on one of the dozens of browser tabs that AGESA updates aren't quite the clean wipe and reflash that you'd expect and they recommended going back to a much earlier AGESA version and incrementally working through AGESA updates. I was doubtful and pessimistic, but for me this worked and not a single BIOS settings was different between the time I couldn't even get 2933 C14 stable and then a few flashes later where 3600 CL14 worked first time with memory training turned off.
F5 (as shipped) > F32 > F40 > F42a (failed to OC RAM as expected)
Flashed back to F30 > F32 > F40 > F41 > F42a (worked beautifully)
I honestly have no idea how AGESA updates interact with BIOS flashes but going back to pre-Zen2 AGESA and then updating for every AGESA update in between actually worked. Sample size of one, your mileage may vary, and all the other caveats ofc. My own janky Asrock B350 board also hated Zen2 (nothing worked beyond 2133) but that was just a broken BIOS altogether and I had to wait for an update before it let me even reach XMP on DDR4-3000.