Tapping noise from the rear

[SamW]

Discovered this noise a couple of days ago, coming from the rear, more prominent in the right side. It occurs only at low speeds, from about 6 mph to 25 mph (10-40 kmh). The noise sometimes seems to go away when just rolling without pressing the gas pedal but occurs again when braking or accelerating but this might not be 100 % generalized. I would describe the sound as something hitting something, with the frequency increasing with the speed. Also somewhat similar to the sound of bad cv axle.

I crawled under the car to look and noticed the heat shield of the exhaust in the rear was missing three fasteners and it was hitting the exhaust and the driveshaft. Put it back in place and went for a test drive and it seemed that the sound was not so prominent anymore but it was still there. Could have been just a coincidence though. Also inspected the CV boots in the rear and they all seemed to be intact and dry, no grease anywhere to be seen. Also haven't noticed any vibrations when driving the car.

I feel like it still could a bad CV axle, I guess they can go bad without having a torn CV boot but anything else to look for before I take the car to an indie? I will also do an another test drive today and let the wife drive the car me staying outside trying to pinpoint the location of the sound.