Experienced the same double speak as an employee: we see your pay is not commensurate with the local cost of living compared to other shops, then doing nothing when asking about raises.
Still seems like could be either hardware or software/firmware at this point. Maaaybe something related to https://www.theverge.com/2023/9/6/23861050/msi-windows-11-bsod-unsupported-processor-error ? Or maybe another case of bios + Windows version problem
There were posts here that said the dead pixel threshold to return was 3 rather than 1 for the FI32U, but I can't find that language on Newegg's listing anymore. Also quotes on here said that it couldn't be returned, but the listing I can see says it has the normal return policy.
Replacing wires sometimes has to be done. But the tech will be able to narrow down which wires are problems pretty well. It may even be the wire (drop) from house to the poles/street, not in the walls. It could be something else.
At this point you might want to pay to rent an Xfinity modem for...