Well I'd say try keeping a good bend in your elbows. In the positive direction and not reverse. Try it out when you ride. Probably won't feel natural and likely your current setup won't make it an easy thing. But you can make a conscious effort and maybe see some indication of what the results might be even if you can't do it for the entire ride.
When I had the most issue with my shoulders, it seems to have been fixed with the narrower 38 mm bars I put on the bike. So that I'm not braced so much to resist side by side swaying motion.
Just being able to keep your elbows bent 70 to 90 degrees might keep your shoulders from bearing too much weight and transferring bumps straight into them. If I'd tried that first before going to the 38mm bars, I wonder if that also will have solved my shoulder issues.
But that much bend might present it's own set of issues for your fit and comfort on the bike till you get other things squared away.
Last edited by Iride01; 10-28-21 at 02:19 PM.