Ahhh strep is nasty!!
Hope you feel better soon! Sorry to hear of the walk-in clinic. I find they can be so hit and miss. Last time I had strep it was really just the wait that was the killer, but once I got in, the doctor (she had a wicked Scottish accent) was all "Och! Aye that be a wee spot'o grungy in therrrrrre" (I had the nastiest looking throat). Anyhow, good luck.
FWIW, my canary wrasse goes MIA very often. What happens though is that if startled, or sleeping, or even just needing a nap in the daytime, they'll swim right into the sandbed and bury themselves instantly. I've only once gotten to witness it happen, he literally just swam into the sand. There was a small "poof" of sand for about a second but once it cleared there was literally NO indication whatsoever that there was a wrasse hidden in the sand at that spot. There are many times I come down to feed the tank and he's gone to bed, he'll be the only one I can't spot, but then the next day he's out swimming again as if nothing abnormal ever happened.
So, ... hopefully this is the case here too.
They are potential jumpers though. I lost my first canary wrasse to jumping. I had an eggcrate cover for the tank but it apparently was no impediment to his trajectory.