Issues with the latest version of the thesis.cls, PDFA and/or hyperxmp?

This issue report might not be the most useful for you, but it might perhaps give some insights. Today I tried to upgrade to the latest version of the template, and was getting constant issues, mostly regarding latexmk. If I compiled the thesis, then the bib, and then the thesis again, I could get a working pdf. However, running only xelatex did not work. One of the issue that came up often was that the version of hyperxmp asked for was not available.

LaTeX Warning: You have requested, on input line 317, version
               `2020/06/15' of package hyperxmp,
               but only version
               `2019/04/05 v4.1 Store hyperref metadata in XMP format'
               is available.

Package cmap Warning: pdftex not detected - exiting.
! Package kvsetkeys Error: Undefined key `pdfuapart'.
! Package kvsetkeys Error: Undefined key `pdfxstandard'.

This was tested on both up-to-date Ubuntu 20.04.4 LTS , and Arch.

Again, the issue could be on my end (such as a missing package), but I could not figure out what it was. Downgrading the .cls file to the version in af9fd476 appears to work as intended. Note that I did not test any other commits in between.

Thanks, William

Edit: It was working on up-to-date Arch, it was another package that was missing (for textgreek). however, this package is installed on the Ubuntu 20.04 LTS.