I'd do the following...
-File a police report
-Notify neighbors that you're chummy with what's going on (to avoid issues and for them to potentially keep an eye out)
-Buy bright motion sensor flood lights and cameras for outside (at least pointing at doors)
-Do some digging on him. See if this is a pattern
I never ended up getting one because COVID kicked in and I can’t travel being unvaxxed. But I had my eye on this one.
Anti Spy Detector, Bug Detector, [Upgraded Artificial Intelligent] KORKUAN RF Detector, Hidden Camera Detectors, Camera Finder for Wireless Audio Bug Camera Detector Finder https://www.amazon.ca/dp/B07VX81HKF/ref=cm_sw_r_cp_api_glt_i_NZJ2CMG1V623WYXKC1PX?_encoding=UTF8&psc=1
Pretty sure they’re talking about something like this. ^(Amazon link, not sponsored)
If you want proof, you can buy hardware to detect hidden cameras on Amazon.
https://www.amazon.com/dp/B07VX81HKF/ref=cm_sw_r_cp_apa_glt_fabc_86BQS1N52YEM31TX7QX5
Here's a link for a bug sweeper, https://www.amazon.com/dp/B07VX81HKF/ref=cm_sw_r_u_apa_glt_fabc_J9NAM2YNGFJPK466PT30?_encoding=UTF8&psc=1
He seems to be using some device under the roof. I was thinking about something like that : https://www.amazon.com/Wattne-Detector-Detectors-Wireless-Upgraded/dp/B07VX81HKF/ref=sr_1_4?dchild=1&keywords=Security+Camera+Jammers&qid=1617563359&sr=8-4
You can get special detectors that help in detecting hidden cameras. https://www.amazon.ca/dp/B07VX81HKF/ref=cm_sw_r_em_apa_i_BKNgFb4EGJ6ZP