How to find the start and end time of each envelope in a signal? Multiple envelopes in 1 signal

I have a signal and I’m trying to count the number of envelopes + their start and end times (each envelope).

I have the derivative of the signal and tried to use findpeaks but it’s giving me more extrema than I need and I can’t impose a minimum peak distance/height/threshold because I have a wide variety of signals.