We all suffer from it. It exists by other names:
or simple, Inattention to Intonation.
What is it?
It is the tendency for us to split the difference when moving the slide between these positions with one note in the middle.
When executing a passage that goes from 4th position to 1st position with one note in between, say, D to F (with an E or E-flat in between) or G to B-flat (with an A or A-flat in between), we split the difference and play the middle note in half way between, resulting in poor intonation. Be careful to keep 2nd position higher or 3rd lower, depending on the middle note.
Hungarian March as an example…the runs that include D, E, F, we tend to play the E half way between the D and the F, or a really flat E.
The poor intonation contributes to a lack of clarity. The condition becomes very obvious when it is pointed out. Half-speed play back will reveal the condition. Once you become aware of it, it is easy to fix.