Multi-bar rests sometimes fail to consolidate

Hi @robert_marc_wren, and welcome to the Forum.

To help us help you it would be useful if you could upload a Dorico project file that presents the issue: most probably someone can tell you what to do to obtain what you need.
Many apparently “janky and buggy” behaviours are often caused by user errors.

Here an important and useful post (in case you didn’t read it):