We just transform from waterfall to agile not too long ago. We used to have UAT session and the users only test when they are available, and we must wait for their sign off before we release to the production. Our release is also scheduled once a month.
Since we started agile, the UAT process is remain the same, as users are not ready to participate in our agile process. Release still remain once a month because of existing governance process still remain.
Our sprint duration is 2 weeks, we plan average 50 points per sprint, and the actual completed points is average 25.