Broken reading of feed

[PedEchsing]

Least I Could Do online comic specifically.
Vienna Version 3.9.0 :7ad9df044: (8175), MacOS Sonoma 14.3

Vienna no longer updates LiCD web-comic (yellow exclaimation). Still updates thru browser-reader Feedbro.
Error: https://validator.w3.org/feed/check.cgi?url=https://feeds.feedburner.com/LICD#l12
Line 12: <atom:link href="https://leasticoulddo.com/feed" rel="self" type="application/rss+xml" />

As far as I know, there's nothing I can do to fix it.
Have sent an email to Laughing Dragon Studios/formerly Blind Ferret Studio(s) pointing to this problem.

HAVE tried changing HTTPS to HTTP... doesn't fix/change anything. (changed it back to HTTPS just in case)
ANYTHING you guys can do on your end? Is this something an update broke?

Thanks for your time.