I never had to reset mine, But maybe in your case since you have multiple unit it could be in the network. I do not blame your network but if for example they have same name it could be problematic. Try change name in network settings. Problem could come from name in openwrt if you use samba service in more than one, you could make change in openwrt settings. Also in your router I suggest assigning ip to mac address.
Thanks for the reply. It's not the network. I tried all of them individually and they still freeze. They all are used as an NVR for cameras. As well as entertainment
I am not familiar with NVR, if this is the only special use maybe it is the source, because mine do not need to be reset.
Seems like Its a memory issue. After I reset it works for a while or if I reset every 12 hours I don't have an issue