2012 Prius front driver side thumping on deceleration

Aloha All,
Mahalo to all who post and especially those who reply. This forum was invaluable during my troubleshooting and repair of brakes recently. Thank you!
On Feb 25-27 I replaced the brake actuator and booster on my 2012 Prius (126,000 miles.) The change went better (and easier) than I expected and I flushed the brake system since I was there. I used techstream to accomplish the linear valve offset (after driving the car to a level parking lot!) Until yesterday all ahs been golden... no dash lights, braking regen happening, solid brakes, no leaks. Yay!
Yesterday my partner noticed a thumping sound while driving. I checked it out this morning by driving it. It seems that everything is fine during acceleration but when coasting there is a thumping sound emanating from what I hear as the front driver side. The thump speed slows down as the vehicle speed decreases and it immediately stops when the brake or accelerator are engaged. I'm at the beginning of my troubleshooting by searching thru the forums and I've not found anything exactly like my situation.
Would love some guidance on what I should be looking at to narrow down the possibilities
Thanks for any input!

@ChapmanF @Mendel Leisk
Thanks for the advice to flag, Mendel!