If your battery connections are tight then you may have a cracked connection inside the battery from banging on it to set the connector. If you jiggle it, you may be getting it to make contact inside the battery again. If that’s the case, you need a new battery unless you want to do that every time and one day it will totally fail and you will be stuck.
Is your battery getting charged? Measure the voltage at the terminals with the engine off and then again with the engine running at a fast idle. At rest it should read 12.6-12.8V, running it should read 13.8-14.2 V.
ssmgtd- how about some pics of your roll bar? I’m sure we’d all like to see what that looks like and how you mounted it.