Issue in Champion Select 6.5

The issue I'm having is really weird when queing into a ranked match. When I accepted the match while in my in game profile, in the Champions section. I noticed that in champion select, that more than half of my champions were no longer there for me to click, search, or even ban. I was able to recreate this twice at the expense of dodging and giving up a little lp for it. I also tried to look closely at what champions weren't showing up in both cases, it seemed to be champions that I had not reached mastery level 3 and up. Was curious to know if anyone else had an issue with champion select, and missing champions.