Yep. Have a touch of it now, actually.

Stretch, massage, ice.. normally can be managed ok, unless it gets really bad.

https://www.mayoclinic.org/...-causes/syc-20372868

"Golfers elbow". Could be any number of things, but possibly due to over emphasising the exit at the rear of the stroke. If you've never had this before and have swam regularly for a long time I wouldn't overthink it, it's probably due to the 3 months off. I swam yesterday for the first time in 3 months and everything was sore. If it continues, alter your swim set, no paddles, mix up your strokes, kick, don't overload your arms, so swim with a PB, core pants, splay your fingers to reduce the load etc. Ease back into it. I'd imagine there are going to be a lot of people with shoulder injuries these next few months!

Did you up your cycling mileage when pools were closed? I’ve had that elbow soreness when I’m doing more bike miles than usual and some hard swimming. I cut back on using paddles and change arm position more frequently on the bike and I can manage it.

Pretty much what I do. I have golfers elbow bad at times, and it seems it's both cycling and swimming hard that exacerbates it. Frequent arm changes, although minor, seem to alleviate it to some degree. And I also swim more longer sets instead of fast or anerobic laps.

Funny thing is that it's only the elbow on my breathing side.