Items are not displayed correctly on the left pane of the AiCloud WebUI under firmware 3004.388.6 (overlapping entries). My main router is a RT-AX88U. With version 3004.388.5, there's no bug (I've tested it twice).
I also have the same issue with garbled info when trying to access AiCloud. I had to return to the previous firmware. I hope it gets corrected in the next update. I really enjoy using Merlin firmware for the last few years.