Thanks for the suggestions. Was quite scared and very careful. Was surprised how loose a few were, and yes, I tightened very very gently...
Tightening Driver Screws
Every time I gently tighten the screws on my speaker drivers, I am quite surprised how effective it is. After about 1 1/2 years, I found about 15% were fully tight, 65% were slightly loose, and 20% were quite loose. Starting to fear I may have to look for the brass screws that some recommend.