@oSoMoN - is this something you could help with? I looked at the chromium snap which doesn’t have any executable stack binaries and put in chrome://gpu and it lists WebGL as available on my 17.10 Intel system (I don’t have an nVidia system).
What is the output of snap version? If it isn’t 2.30 or higher, can you try with the snap from beta (sudo snap refresh core --beta)?
If you launch the snap from a terminal, what are the differences with the terminal output between devmode and strict?
If you install the snap with an executable stack, and then you add this to /var/lib/snap/apparmor/profiles/snap.polarr.polarr:
/dev/nvidiactl m,
then run sudo apparmor_parser -r /var/lib/snap/apparmor/profiles/snap.polarr.polarr, then rerun your application, does it make a difference (I don’t expect it will, but it will definitively rule out execstack)?
Does stracing the snap reveal anything interesting? Note that sometimes it is handy to compare an strace from running in devmode and running in strict mode.