I had the problem of the GPU (6800XT and RTX4080) being stuck in 16x v1.1 and the results were terrible, I got like 30% of the performance. So it can happen, but it can also be a reporting bug. Running benchmarks should be the first thing you do, som...

0.975V is already low, I guess you aren't running a memory overclock? Try with 1.20V, just to see if there is a difference. 

Try slowly lowing your SOC voltage from where it currently is and see if it helps.