Hi! How do I reset the bar-lenght in m.102b here?
You can move the first of the 16ths over to the left in Note Spacing mode (it’s one of the submodes of Engrave mode, accessible through the panel to the far left of the main window). Once you’re in that mode, select the square handle above the first 16th and use Cmd/Ctrl-Alt/Opt-Left to move it (or just Alt/Opt-Left for more granular movement).
The cause of the distortion is probably the length of the Tempo1 (q.=55) text - Dorico won’t allow the accelerando to overlap the previous tempo marking by default.
A technique which I have used in a similar situation is as follows:
In Engrave mode, click on the accelerando, open the Properties panel and in the Tempo section, change the X value in Start offset. You will need to enter a negative value to move it to the left.
Thanks! That works well 