Like in one of the more recent (https://forums.primetimer.com/topic/122533-season-9-discussion/page/3/#comments) episodes, he's perhaps at most, only in a scene with another actor for about a minute of the entire episode. The rest is likely comprised of stand in shots where it’s clear either he is talking to a stand in or vice versa. Somebody on Reddit pointed out (https://www.reddit.com/r/television/comments/ryu161/has_anyone_caught_a_recent_episode_of_the/) that there's a scene in which Murray is presumably hugging Beverly, and in no small part due to the wonky editing, you can tell that it's actually two stand-ins hugging each other. Somebody else noted that there must have been a scene where Erica was in the background when Murray was talking, and the kitchen appeared to be green screened.

I can’t stand to watch the show anymore. They should recast the part or say he’s living with his ailing father or went out of town on a golf trip/sales convention..whatever. I don’t think they should axe the character but dubbing him in is too noticeable. Maybe have him on the couch napping …they had recasts on Bewitched and Roseanne that went on several seasons. Maybe they could do it here too.

I’m sure they will find a permanent solution by season 10 but it’s midway through the season, it would be kinda odd to recast now