I had this problem at home and at work, both of them used the newest version of Animate and both as the same problem. i noticed the pattern on how they show up in Animate when i used a mac but i haven't tested too much on the windows version but i noticed the same problem.
I am also using a very new mac, maybe it might be the cintiq driver's that has a problem.
the dot only shows up when the stroke slows down at the end when releasing the pen from the tablet, then the dot appearse. when making fast brush strokes then it does not show up. (showen in the video link provided)
Here is a video were i try to replecate the problem
I'm using a mac with a Cintiq 16 HD (used in the example) at work and Windows for the Cintiq 13 HD i have home.
iMac (Retina 5K, 27-inch, 2020)
prossesor: 3,8 GHz Intel Core i7
memorie: 8 GB 2667 MHz DDR4
graphic: AMD Radeon Pro 5500 XT 8 GB
It's not a problem i have had for a long time, not sure if it is gonna just go away at some point but it is a bit annoying at this moment. I'm tempted to try too downgrade to a older version of animate just to see if it will go away.
I'm happy to provide more info
Make sure you download the latest animated version 21.0.3.