Nonstandard (possibly insufficient number or incorrect placement of) augmentation dots for certain chords
GIT commit: 3c7a69d
It appears that Musescore sometimes omits the augmentation dot for a specific note within a multi-note chord (a four-note chord in the example screenshot), placing only three of the dots. It's possible that the fourth augmentation dot is placed by MuseScore in the same position as the dot for another note and is therefore not visible as an separate marking, or that MuseScore is using a different notation standard or set of rules.
Some notation standards or rules suggest moving one or more augmentation dots up or down to an adjacent space to accommodate the same number of dots as are present in a chord. Of course, if two or more voices are notated on the same staff at the same position in time, and both voices include chords with augmentation dots, and both voices are very close to each other in their vertical alignment, it may not be possible to adequately display the full number of augmentation dots required or suggested by the chords.
Compare chords and augmentation dots of first and second measures of screenshot "augmentation-dot-anomaly2.png. Score attached; anomaly exemplified at measures 76-77.
Example PNG screenshot attached.