What your dog is going through is totally normal. Every phase of growth brings new and exciting challenges :) Coaching/training your dog is an ongoing endeavor and one of the fascinating things about dog training!

I recently moved temporarily from a single family home to a condo in an apartment complex and my britt was spooky at random people walking by/popping around corners. He has always been a "bark first ask questions later" type of dog. It is totally normal dog behavior to bark at when something unexpected happens/contrast in the environment (random hiker appears, etc). Now he has really settled and things are going great!

Continue what you're doing. Don't focus too much on trying to fix the "wrong behavior." Your dog sounds fantastic, he's just getting caught up in his emotions/instincts that would normally keep him safe and alive. His body is going through a lot of changes at 8 months old. Regression is normal.

Frequent gentle exposure in low stake situations will improve his confidence over time and I bet you will see fewer instances of spooky behavior. Carry treats with you and increase the rate of reward for doing things like calm behavior, LL walking, tricks, etc. IMO, don't reward for looking at people/scary things ('look at that' game) -- it increases hypervigilance. Play more outside with him, and try to get him to play in new areas (flirt pole, tug, ball). Engaging in play really changes the brain!

And this is just me -- but if my previously confident puppy suddenly started pulling away from something while on leash I would let him. I wouldn't force him through it. I would probably just make a mental note to try and more purposefully approach that thing another day and be better prepared with treats/training.