Google chrome will not download PDFs specifically - all other downloads fine

Old and crusty tech support guy here - started on Dos 3.3 and Windows v1. I also remember Microsoft Bob! Hello to any and all similarly crusty techs :)

My office PC has started playing up when trying to download PDFs. I use chrome as my default browser on Win11 and when I try to download a PDF, the behavior has changed in the last 12ish months where it immediately fails, every single time I try to download a PDF.

Under SETTINGS > Privacy and security > Site settings > Additional content settings

PDFs are configured to be downloaded instead of displayed in the browser. Made that change about 3-4 years ago and had no issues until some time \~8 to 12 months ago when it started to display an error message for PDF downloads ONLY - has a red download icon with a diagonal strike mark across the icon next to the download filename. Below that it says "Check Internet connection".

Any and every single other file format downloads fine, I have a perfectly stable FIOS internet connection (maybe one outage every three years) and get 315/330 for my speeds at 300mbit rated connection. PC is hard-wired and the in-wall cabling (which I ran and terminated myself) tests good at 10Gbit with my Fluke LinkIQ.

Anyone else come across this issue? I may try uninstalling and re-installing the browser etc. but am hoping someone else knows the specific solution to save me a little time.

Thanks in advance for any pointers!

***<EDIT> I edited this post whilst it was awaiting mod approval to say that it turns out it's a problem with my old and crusty webmail, not chrome. PDFs download fine from Gmail webmail but not my aplus webmail</EDIT>***