Apparently random rendering artifacts with some PDF files
An issue was recently opened on Gnome evince project about some visual artifacts (more specifically some random letters in huge font sizes) appearing when viewing some documents. You can find many details on the original issue: https://gitlab.gnome.org/GNOME/evince/issues/1244
Reporters (including me) are on bleeding-edge distributions (Manjaro or Arch) and the bug appeared only a few days/weeks ago.
Several examples of PDF files causing this are available in Evince issue thread, I can provide more if needed.
As this started around the time of poppler being updated to version 0.80, I tried to revert to poppler 0.79, but didn't changed anything. I am not very available soon, but will try to help if you need more information.
For information, the list of packages and versions installed marked as dependencies of poppler on my system:
poppler 0.79.0-1 libjpeg-turbo 2.0.2-1 gcc-libs 9.1.0-2 cairo 1.17.2+17+g52a7c79fd-1 fontconfig 2:2.13.1+12+g5f5ec56-1 openjpeg2 2.3.1-1 lcms2 2.9-2 nss 3.46-1 curl 7.65.3-1 poppler-data 0.4.9-1