Blocked neck

Hi everyone,

My neck keeps getting bocked. 1-2x a year. The axis of my head ends up shifted to the LEFT above the axis of my body (unfortunately the pictures don't seem to be loading) and I can't tilt my NECK to the RIGHT (I can tilt my head a little bit), it just doesn't go further and I feel a sharp pinch around the part where the middle of the trapezius attaches to the vertebral column on the SAME side, ie. the RIGHT side. I can turn my head left and right, but I also feel a less intense pinch when I turn my head all the way to the right.

It's usually gone after a week and sometimes appears with physical activity (front crawl swimming), sometimes not.

I mentionned it to my physiotherapist while seeing him for a different problem and he recommended reinforcing the muscles by doing that exercise where you push your head back to get a double chin (know what I mean?). I haven't noticed any difference unfortunately.
Tried going to a chirorpactor but wasn't happy with that. I liked the short relief but the main block didn't go away any faster.

I've been trying to mobilise my trapezius, which is very tense on the right side. This has been feeling good but imy neck just got blocked again out of nowhere.

There's probably no way this can go away faster, but I'd really like insight on
- where it comes from
- which muscle gets blocked
- how not to get it anymore. What kind of exercices?

Any advice welcome!