Igor Russkikh

Warning about the firmware can be ignored. What do you mean with "drops down"? It that link goes down and up? Can you provide the output of "sudo dmesg |...

Thanks. From log it looks like a hardware issue. It could be: - because of cabling. What cable, length and quality you use? Oficially, rates > 1G needs cat6. -...

Cat7 is for sure more than enough. I can only think about some incompatibilities with the router. But again, I can't explain why it does not happen on windows. One...

@ldhasty, how did you checked the number of drops? Could you provide the following output before and after the transfer In good and bad cases: `ethtool -S enp1s0`

in kernel driver did not reported "dropped" counter. Thats why you don't see it increasing. I guess its always increasing, in both drivers. You may check in kernel driver ethtool...

Could you please validate latest 5.13.x ? there was a similar problem which was fixed/backported in there.

So you mean 5.13.19 also has this problem??

The problem is floating between the kernels, still no root cause found.

This is most probably because .deb installation sequence does not take into account the module dependencies. As a workaround please try doing `modprobe ptp crc_itu_t` and then repeat installation. But...

Can you paste here your dmesg log? it should have error message in it.