Multi measure rests butting next to one another. how to combine?

hello, i looked at the turtorial on multi measure rests and cannot find an answer. attempted all types of key stroke combos to attempt to remedy.

i have a multi staff score and when isolating one of the lines (parts) i have a couple instances where the software has produce multi measure rests for that instrument when silent which is great but i have a 7 measure rest immediately followed by a 4 measure rest on the same line and cant find a way to combine them for an 11 measure rest.

sorry, im sure im missing something here.

-mike