Shimano 105 R7000 drivetrain makes crackling sound
It sounds like your derailleur indexing is bad. The 'crackle' is the chain trying to climb the shift ramps on the next largest sprocket then falling off.

It may be that your derailleur indexing is badly adjusted. You can run through a rear derailleur adjustment process and see if this fixes the problem.

You should also check that your derailleur is aligned properly. The derailleur hanger can get bent so that the derailleur cage is not longer parallel to the rear wheel. If you pick rear wheel of the bike up and look down the line of the chain you can see if the cage is grossly out of alignment if it is not parallel to the chainrings. A bike repair shop can check and re-align the hanger. 

Another possibility is that the chain is catching in one of the jockey wheels in the cage. If you hold the rear wheel off the ground and pedal manually you should be able to see this easily.