The error is about PCIe connection, not about SSD flash medium. Also, those errors are usually sporadic so it is rather difficult to confirm that different kernel version fixes it.
I would reseat NVMe in any case, sometimes this cleans up contacts.
As always with such errors, it can be device (NVMe) and it can be the connector or it can be the PCIe switch to which this connector leads.
Unless these errors happen very often I would not worry.
The system is a quite reputable two year old All-In-One system that cannot be opened so easily in order for me to gain access to the parts inside. I think it’s quite strange for a two year old system to have an nvme that’s degrading already. Nothing is impossible though. Since these messages have appeared only once so far, I’ll follow @arvidjaar 's suggestion and see if they appear again.
There is one thing that crossed my mind though, since I’m living in a provincial area and I have found bugs crawling around. Can bugs that are possibly living or moving inside the computer cause such problems? Have you ever come across anything like that?