Board Thread:Episode Discussion/@comment-24993958-20181026055523/@comment-4141313-20181108215229

Jayne probably does have serious self esteem issues still, and considering how wreckless he was facing Cinder and disregarding her threatening to kill him, he may think very little of himself and as such still not mind others mistreating him.

Not saying Weiss mistreates him anymore, she just didn't thank him. Her pointing out how helpful he'd be for Ren and their little seen eating together show she isn't as mean to him as she used to be.