I'm familiar with LTS, I have an account with them. Although I don't use it much because = years ago I lost 2 separate bids when the customers contacted LTS directly. LTS aggressively priced against me (giving customer 5% off dealer cost). Same $hit Lutron does to small dealers once in awhile. Makes no sense what-so-ever since ultimately they are competing against themselves and getting 5% less money. But whatever, left a bad taste in my mouth. Also note: although LTS cameras have been great. I have found the LTS firmware on their DVRs & NVRs to be very buggy. Make changes in the software and it refuses to take. Some things might revert after a power failure. Or features just not working the way they are suppose to. Add to the fact they discontinued the residential video Doorbell (Hik is still making a great one they can OEM), and I avoid LTS like the ....
As to your current problem = Like I mentioned, LTS has buggy firmware. The thing that should be done NOW! Go install the latest firmware (NVR5_V4.61_230110) for that NVR. It literally just released 14 days ago. This may fix some buggy issues. Note: If the current firmware is older than V3.4.96, your screwed (can't upgrade the regular way) and very likely what's causing issues. Also note: after doing the firmware upgrade, go thru ALL the settings to make sure everything is how you want it - 8ch system should take less than 30 minutes to get thru the whole menu, even being as meticulous as me. You can also save a copy of the config file.