We run 5 ACAD 2019 stations, two of them have a similar problem as you explain. One unfortunately is mine, my first issue with 2019 was the selection issue, that was rectified with a hot fix and a reissue of an update. The second is this issue and I believe they could be related. With the selection issue, speed was critical, if you performed your crossing windows slowly, selection worked, but if you sped up ACAD did not select the appropriate things.
Now, watch my attached video, and note that when I select a point to dimension, the selection icon is "on" when I select the point, works most times, but not all. If you look closely the point is acquired at the precise cross hair position and not the snap position, it is as if ACAD has a slight delay from "enter" command to actually carrying out the command, and at that time the cross hairs have already moved away.
I agree with skifx, when he states his years of experience, implying that this is not operator error, but a definite bug, I have 18 years ACAD experience, I do things instinctively, and as soon as I started using 2019 this issue arrived.
This issue is very frustrating, and will most probably cause incorrect dimensioning, resulting in rejected products.