Reolink RLC-823a, running @ 1.00 keyframe on both main and substream via custom firmware. My stream will gradually get further and further out of sync in Blue Iris. The Reolink UI is about 10 seconds ahead at this point, meaning it takes any PTZ commands issued via Blue Iris about 10 seconds to come across, making it, along with things like live 2 way audio, useless.

It might have to do with direct-to-disk and I'm testing re-encoding now, but that has a whole other set of issues. You can't record the main stream if using main+sub with re-encode. This wonderful tidbit is buried in the help file.

Anyone dealt with this? The PC/network are more than beefy enough to run this one camera I am setting up. Main and substream are both synced. I'm just at a loss.

I'm not familiar with that model but with other Reolinks I have found that you must use the RTMP stream rather than the RTSP - the later has drop outs .. RTMP is stable when using 1 stream. The problem for me is the beta Reolink Firmware for my 410s and 520s drops support for RTMP when you get the version that fixes the key frame interval. In the end I just went back to old firmware with RTMP support and gave up on sub streams.

Have had exactly the same problem for some time, running 16 IP cameras through BI on dedicated server - Reolink support were great and attentive and have provided me with updated firmware for the cameras which 2 days on seems to have reduced the lag to less than 1 sec consistently. Well happy and relieved. Can provided link to firmware is contacted.

I'm in the same boat. I have a 14 Reolink cameras spanning 7 different models. The worst offenders for me are:
e1 zoom
rlc811a
rlc81ma
trackmix

The only ones that seem to work well are Duo2, cx410 and the doorbell.

You can't use RTMP at full resolution on the 4K cameras, you will only get the substream. Some tips that improved, but did not completely fix things for me include:
- Set FPS to 15 or lower on both streams
- Set constant frame rate
- Set interframe space to 1x
- Don't use the substream on the telephoto lens of dual lens cameras OR
- Don't use the substream at all (I noticed that the substream can lag more than the main stream on some of my cameras, especially the rlc811a)
- Disable as much stuff as you can on the reolink camera (e.g. recording to SD card, push alerts, etc...)
- Reboot the Reolink cameras daily

I've found that restarting the camera in BI fixes the issue so using Watchdog is probably going to be my next attempt. I'm also going to reach out to Reolink support to see if I can get one of these firmware's that seem to fix the issues.

Looks like a typical cut and paste straight from IPCT.

My RLC-811A works flawlessly after flashing some beta firmware posted here back in May.