Perhaps a rod with a smaller diameter, so less friction?

You could try putting the ring inside the tab, hand tacking at top and sides. That style curtain is not meant to open and close. They are designed to be stationary.

I don't have back-tab curtains. I came across this post (link below) that may be helpful to you. If you scroll down on the comments, you will see that the original poster discovered a spray that made the drapes glide easier for their curtains with rings and also for their tab-top curtains. My local Joann store was all out of this spray, so I have not had a chance to try it out, yet.

Another idea is to add your question to the sewing forum.

Curtains - Glide Easier

If you try a drapery pull baton you may have better luck . Trying to pull the drapes from the bottom only snags them at the top. You need to pull them from the top over.