Entire House Lights Flickering

This is an odd situation for me. When I originally implemented the RadioRA 2 system at a clients house (one year ago) all tested and configuration was fine (client only had one electrical panel). Just recently the client had an electrician come out to install a sub-panel in his backyard, and now the client says ALL lights connected to a switch/dimmer/keypad I installed are flickering. His electrician obviously is going to say it's something with the switches, so I was hoping if anyone has any thoughts to why this would happen AFTER a new sub-panel was implemented.I am already scheduling to go back and check for loose connections.Switches & Dimmers used: RRD-8ANS, RRD-HN4S, RRD-HN3S, RD-RD, RRD-10D, and one PJ2-4B (Pico)Thanks in Advance for your thoughts and suggestions.

Hello! Thank you for your inquiry. It is possible that the subpanel has created a neutral interaction. LED lights are not naturally resistors and a heavy load coming back in on the neutral can cause them to flicker. We would advise in tracing the neutral for the subpanel and see if it connects or interacts with any of the lighting circuits. It may need to be swapped to a different phase on the panel.

IF it;s truly ALL I would look at the panel he pulled the new sub from. Look for loose neutrals on the neutral bar. Bet the electrician moved a few things around and didn't check all was tight.
I am an electrician and it's usually not all. "All my light are not working" " half my house isn't working"