Yeah, every time I took a car to bare metal I had problems with it later. I'm no professional body shop though. I hate body work.
My car was flaking and peeling all over, I just sanded the last poorly prepped coat off the body of the car with 120 grit on a DA, except the bumpers. They were cracked and needed to be stripped bare to fix the cracks and fill some big battle scars. I tried SEM flexible bumper stripper... but it's expensive and you need 1 can per bumper, per coat of paint being removed judging by my experience with it. If the paint is more than one coat thick it'll cost you a fortune. I had 7 coats on mine on top of the factory paint. I tried the paint stripper walmart sells that says "not for plastics" and it worked, but swelled the bumper (it unswelled as it dried). I only did a small 1ft section of the front bumper with it, it still took a whole quart can and multiple applications to get through all those coats. Ended up DA sanding with 80 grit, then 120, then 220, then hand sanding with 400. The sanding worked much faster.
My car was flaking and peeling all over, I just sanded the last poorly prepped coat off the body of the car with 120 grit on a DA, except the bumpers. They were cracked and needed to be stripped bare to fix the cracks and fill some big battle scars. I tried SEM flexible bumper stripper... but it's expensive and you need 1 can per bumper, per coat of paint being removed judging by my experience with it. If the paint is more than one coat thick it'll cost you a fortune. I had 7 coats on mine on top of the factory paint. I tried the paint stripper walmart sells that says "not for plastics" and it worked, but swelled the bumper (it unswelled as it dried). I only did a small 1ft section of the front bumper with it, it still took a whole quart can and multiple applications to get through all those coats. Ended up DA sanding with 80 grit, then 120, then 220, then hand sanding with 400. The sanding worked much faster.