What do I do?

[Bogertophis]

...
My SO has a bullsnake (I believe), and he can be a pusher. His face healed cleanly except the nares are nearly completely closed, but he often sleeps with his mouth wide open and will randomly let out a loud whistling sound that could be mistaken as an RI. So if your retic is a pusher and has damaged his face, that could certainly be another cause. As mentioned, larger enclosures can help, as well as adding some hides and things to climb around in/hide behind.

Same exact thing with that male bull snake I had... They're active diurnal snakes in the wild, not always the best in captivity so no enclosure is big enough
in their opinion, lol. Cool snakes though, & not all of them "push".