Diagnosis
This is classic symptom of the satellite's placement. You're likely in a 'dead zone' between the satellite's signal and the router's signal, and your device is stuck on a weak connection instead of roaming properly.
How to Fix It
Reposition the satellite. It should be about halfway between the router and the problem area, not at the edge of it. The goal is for your device to always have a strong signal to *one* unit, not a medium signal to two.
If That Didn't Work
Your device may have poor roaming logic. On the Orbi, go to Advanced > Setup > Wireless Setup and temporarily disable 'Fast Roaming' and '802.11k/v' assistance. This can force devices to reconnect more aggressively to the stronger signal.
Heads Up
Mesh systems aren't magic. If the satellite is in a closet or behind a metal object, its signal is crippled. Placement is 90% of performance.