Internal thread not sticking to inner wall
I do a lot with printed threads, and find this problem creeps up mostly when the filament is wet. Higher temperature (like 220) can partly compensate but it's better to dry your filament and store it properly to keep it dry.
Assuming standard metric thread profile, though, these are also pretty severe overhangs for a concave extrusion (where motion of the head will tend to pull the way you're seeing) unless you use very thin layers. You probably need 0.16 mm or thinner to print reliably (independent of pitch, though finer pitch also needs finer layers for other reasons), and limited acceleration for outer walls (I use 500 mm/s²).  If you slice with &quot;outer walls first&quot; turned off, you may be able to get by with thicker layers, provided you have everything else tuned perfectly to ensure the outer wall sticks to the previously extruded inner one (i.e. flow rate perfect).
A contributor to your problem could also be underextrusion due to oozing during combing. You might try setting max comb distance very low (like 0.6 mm, around what I use) or turning off combing and see if that helps.