It's not my Asus Mesh system with the three XT8 Mesh Clients, because the XT8 Mesh Client in the hallway is configured as an access point and connected via LAN cable to the central Asus XT8 router in the study. As I said, all of my approximately 40 WiFi clients here have absolutely stable and very good WiFi; this problem only occurred with the Reolink Doorbell WiFi. BTW: I've been working in IT for around 30 years and know the topic pretty well.
Nothing I tried and tested could solve the problem. Maybe the Reolink Doorbell Wifi also had some kind of defect, but the fact that various other users have also experienced exactly the same problem and has been doing so since 2023 speaks against this.
@TonyR
I also tested 5GHz. The same problem.
Just a small excerpt from the WLAN client list to show a few example connections.
1. DB61i = Outside next to the front door and about 4 meters from the XT8 Mesh Client in the hallway.
2. Google Küche = Google Nest Hub in the kitchen which is right next to the front door. The Google Nest Hub is about 5 meters away from the Mesh Client in the hallway.
3. Iskra MT176 = IR reading head on the electricity meter with ESP8266 in the utility room in a metal/sheet meter cabinet. There is a wall (Wooden frame construction) between the utility room and the XT8 Mesh Client in the hallway.
4. Google Arbeitszimmer = A Google Nest Hub on the first floor in the study, but it connects there via the XT8 Mesh Client.
5. Growatt Shinestick = A WLAN stick with ESP8266 on my PV inverter outside on the terrace. The WLAN stick is approx. 7 meters away from the XT8 Mesh Client in the hallway.
As you can see, all of these devices have a very good WiFi connection, whether 2.4 or 5GHz. All WLAN clients have values between -30 and -60 dBm. The value of the Imou DB61i is the "worst" at -60 dBm. The Reolink Doorbell Wifi had an even better value at -54 dBm, but there were still interruptions and timeouts.
For me, the Reolink Doorbell Wifi issue is over and the part has long since gone back to Reolink.
I am very satisfied with the Imou DB61i, which is virtually identical to the Amcrest AD410, which is also from Dahua, and it also offers me other advantages in conjunction with my Dahua NVR. It is also fully supported by my NVR, so the AI works on it too.
It can also be used as a Dahua video doorbell under DMSS. The Imou DB61i is also fully supported via SmartPSS.
PS: The Imou DB61i can also be integrated into Synology Surveillance Station as an Amcrest AD410 and is therefore directly supported by Synology Surveillance Station as a video doorbell.
PPS: Under Home Assistant it can be integrated either via the Dahua addon from rroller - which unfortunately is no longer maintained by rroller, or via Onvif integration. With the Onvif integration, person detection works via IVS and the bell push is also available as a sensor under Home Assistant via Onvif integration. That wasn't the case with my Amcrest
AD110, for example.
So that was enough “advertising” for the Imou DB61i.