Mastery 6 garen dissapeared

ok so I don't have screenshots of before this happened since I didn't expect to need them, but I had 2 master 6 tokens on garen. I got the second one this morning. My pc bugged out and I had to get to work, so I didn't merge them into m6 garen yet (I was m5 garen for a while now). So this evening I play a game and pick garen again. I get an S-. I remember that I still need to combine my 2 tokens with one of the 2 garen champ shards I had. I upgraded it. One suspensefull animation later aaaaaand.... nothing. The tokens dissapeared. The champion shard dissapeared (one of them, the one I used, so I still have one). and I'm still M5 on garen. Why? Can you fix this? not that it's impossible to get m6 again but it's kind of a bummer to get m6 then have it bug out into nothing and lose a champ shard in the process.

GAREN DEMANDS JUSTICE!!!