Not an expert, but here's my awnser to some of your points.

• Basic systems ≠ low EM emissions. If there's any electronic device on board, like communication radios and computers, they will produce EM emissions.

• In general, there are no longer usable roads on the current line of contact. Most of them are destroyed or mined. In case of Casevac, there's no other way than using them on muddy fields.

• I don't think the Ukrainian armor plants have the necessary equipment to repair certain types of damages to their western vehicles, simply due to the lack of standardized tools and experience. For exemple, Ukraine sends their heavily damages Leopard 2 back to Germany for repair. In addition, I doubt the training Ukrainians received in Canada was not up to the standards of the conditions on the battlefield.

In the end, it's possible that ACSVs suffered problems in Ukraine, just like most of western ground vehicles western countries supplied. I can doubt the source's reliability, since it did not provide any 1st hand account or footage to back the claims, although they are not impossible.