Which coordinator do you use?
Connect ZBT-1
If the network is not well meshed then the link quality could be too low for the sensors to reliably stay online. Adding repeater devices (mains powered devices like bulbs) could help here.
Running six of these over three floors (2x basement, 2x main floor, 2x upstairs): https://www.amazon.com/gp/aw/d/B0DQTFM1T6
Soil sensors: https://www.amazon.com/dp/B0DH25W72N
One is within a few feet of the coordinator. I try to just not look at the network visualization as it just causes more headaches, but I have zero "green" connections... Maybe those plugs are just garbage though, IDK.
I'm slowly converting everything to run on these little 1 liter PCs. I have three so far (four if you count the Mac Mini NAS), and an Optiplex 7050 SFF that's been a bit hotrodded with a 300W XE3 PSU, Precision 3420 CPU cooler, & Noctua fans w/extra intake fan.
I like the Optiplex for obvious reasons, but it's a bit of a power hog with the i7-7700 and 48GB RAM. I haven't measured them individually, but if I had to guess, the Optiplex probably accounts for a solid 1/3 of the power usage in my entire homelab.