your build is old 2019, check the server hardware logs, and if there are no serious errors you could try to upgrade.
your server manufacturer may have a customizable image to upgrade to a newer build.
You required involved to hardware vendor, they will run hardware diagnostic utility , and I am sure this is not VMware issue
"The network card I am using is RTL8125BG. I understand that this network card will no longer be available in versions 7.0 and later. 6.7 is the last supported version, but I cannot install it."
I was referring to update the patches (Build) within the same version 6.7.
Another option is to update the server firmware, to see if with new levels it can detect any hardware errors.