You are describing my experience with thrombosed veins. When one clogs the first thing I notice is localized skin puffiness. See if you can feel a hard vein. Sometimes it’s difficult to pinpoint until the swelling subsides enough.
In my case the vein usually clears within several days (3-6), but remains extremely prone to clogging again. Sometimes it will be ok for a PE session or several, then the cumulative stress catches up and it plugs.
If you are dealing with the same thing you might be able to alter your PE approach to work around it. Or maybe not. These can be extremely frustrating and take a long time to heal.
It won’t heal if you keep aggravating it, so resist the urge even if it means taking more time off than you’d like. I fought with one of these for a long time before giving up. 1-3 days of hanging made the vein clog. After a week or so off it would clear. Hang again for a day or two, rest most of a week, hang again and so on. I wasn’t in the mood to take a break. I was able to work around other thrombosed veins until they eventually fully healed, but this one was right where the hanger attaches. Finally I realized I was spinning my wheels by continually aggravating the injury while not hanging enough for a gain.