Worth noting that updating too far (i.e. to a recent/current driver) appears to introduce crashing issues. Probably best to try that exact one mentioned.
I have no experience with this card but looks like there is a second driver package “Crimson Edition Beta” that is slightly newer. Have you tried that? You could also try downgrading the driver to a previous release. Aside from that, shopping for a used Nvidia graphics card…
Zwift uses more complex object lighting for avatars within a certain distance of your own and it looks like that object lighting isn’t running. If you’ve ran through all the driver options for your GPU I’m not really sure there’s many options left other than trying a different GPU if possible.