It looks like you need to use the value always, rather than yes, if you want to do session refreshes when the other side claims not to support them. However, there may be a bug in this area, see:
I’m unlikely to investigate this any further, myself, and I get the impression that no bug report was ever raised. Also, Google still hasn’t caught up with recent mass URL rot in the documentation and the search feature in the documentation is not getting me to the page that documents all the res_pjsip settings, which means I can’t even get to a primary source for the “always” value.