@KaJay Sorry, I missed that on your update. @Artie M Has been years for me as well. I don't believe it is ever a 402g failure, but a 415 failure.
As to whether the special $10,000 can be a combination of EE deferral and ER contributions I do not know. If it can, then there is no 415 violation. If it cannot, then the excess 415 limit is the roth deferral over $2,633 as the tax person suggested.
I believe 415 limit excess must be refunded by the December 31 following the plan year, so you would have until December 31, 2025.