0,2 nozzle partial clog

Hi, I need your help: I print multicolour piece with a 0,2 nozzle. I already did 4-5 différent pieces 2 months ago and no trouble. I would like to print the same model (but 40 unit on the plate) and the trouble started: under extrusion only on an overhang. The speed was too slow and the only thing I found is to downgrade to Bambu studio 1.10 version. the problem solve at this place but now I have under extrusion after a colour change. i tried with less pieces (4) and it was the same. i thing it’s a small clog because when I stop the print and after restart just with the normal purge it’s ok until the colour change (not at each change). i use the Bambu profil and pla basic . I tried to decrease the temperature because I thought its was an overcooked in the nozzle, it was a bit better but not 100%. I bought an a1, I did another modele but with the 0.2 nozzle I have the same problem.

I dried the filament, same.

I think I upgrade the x1c between the first batch without trouble but not sure. Now I’m with 1.08.05 and my a1 with 1.04.

Any advise? Maybe downgrade the x1c to 1.07?

if yes, for the a1 which version is the best (or like the 1.07 for the x1c)?