Conversation so far:
What kind of personnel changes were happening with Martha and the Vandellas?
Motown struggled to find good material for many acts after the exit of Motown contributor and Reeves' mentor William Mickey Stevenson in 1967 and Holland–Dozier–Holland in early 1968.
Did Martha and the Vandellas still have any hit music during their personnel changes?
Martha and the Vandellas continued to find success with the singles Love Bug Leave My Heart Alone and Honey Chile added to their already extended list of charted singles.
What else happened with Martha and the Vandellas in their career besides the personnel changes?
That same year, label changes had started to take effect.

Question: What label changes?
Self-contained rewrite: What label changes started to take effect with Martha and the Vandellas during their personnel changes?