I had a problem with my large slide on a 29L Arctic Fox. When extending it it stuck and then released with a loud bang. The awning cover was torn and the brackets bent.
I cut off the fabric and removed the brackets and the hardware associated with the awning cover and the slide worked flawlessly during the rest of the trip. Fortunately the trailer was new and under warranty. The dealer replaced the awning. The dealer had no idea what caused the problem,.
If you have an awning perhaps it is causing the noise. If you do, I would remove it and see if the problem goes away.