I am sorry I have not tested on 8.5.x, I have been on 9.0 for a long time now but I now that many people have no choice in the matter so I hope it can work for 8.5.3.
A couple of things to check.
Which version of swiper are you using?
Did you add swiper Before configuring the project for Source Control? Swiper needs the source control association set up before it is added otherwise it will not add itself to the project properly. I have just released 1.0.2 to address this problem.
If you did add swiper before configuring SC, try removing swiper and adding it again.
Are you using 'Build Automatically?' and do you have 'Enable Automatic Export of design elements' set in the Domino Designer -> Source Control preferences.
If you right -click on a file for example a view and then choose swiper -> Filter selected , does this filter the view metadata?
Last resort, we can do some logging.
If you go to File -> Swiper -> Start Logging
Then do some operations, e.g. add swiper to a project
save a file
build the project (Right-click on project - > build)
right-click a file and Swiper -> Filter selected
Then go to File -> Swiper -> Stop Logging
then there should be a log file in your %HOME%/.swiper/swiper-log0.0.xml
If you can submit this log via github (defects link above) under a new issue 'not working in 8.5.3' and attach the log I will have a look at it.