I've had issues with the browser agent in the past. Found out that the X11 |
SunOS  or  [Mozilla/4.5 [en] (X11; I; FreeBSD 2.2.6-RELEASE i386)] user agents
work on sites that limit those. Give it a try. I do not know anything about
the AVIF issue because I usually deal with standard PNGs, JPGs and
non-animated images.