They’re likely in too far and collecting blood directly from your cervix, soaking just one part. Blood then takes the path of least resistance (through the soaked part and down) and never reaches the rest of the tampon. The blood needs to pool in your vaginal canal to evenly coat the tampon. Try inserting a bit shallower or at a different angle and it should resolve. You may need to switch brands or absorbencies to maintain comfort.

3