RBR750 Throttling WiFi to 100mbps on Gigabit Connection

I hope someone can provide some insight. I currently have an Orbi mesh system set up in my house. One RBR750 router, and 3 RBS750 satellites. 

The RBR750 is connected to a Nokia XS-2426X-A gigabit router (verified set up in bridge mode by internet provider) via a LiteWave LS108GP switch. All cables from the modem to the switch and the switch to the router are Cat 5. 

Here is my problem: the two desktop computers hard-wired to the switch continually enjoy +/- 960mbps connections without interruption. The Orbi, however, continually throttles the WiFi speed down to 100mbps. At first we thought it was an issue with the Nokia modem not being in bridge mode, but through a series of trial and error, we know we can restore the full 960mbps WiFi speed by rebooting the Orbi router only. We can leave the modem powered up, as well as the switch, and just reboot the Orbi, and the WiFi speeds go back to “normal”(at least for awhile), so we don’t think it’s a bridge mode issue. Any thoughts or suggestions?