Adobe Connect week signal strength

Hi

As a teacher of English I use adobe connect to host 20 students. I use an imac (big sur) and laptop with windows 10 using ADOBE CONNECT APP. I connet my machines (computers) through an Ethernet cable. I should explain that my internet connection is a home connection. My home connection is like this: There is a radio antena on the balcony which leads the internet to my home through a cable and the cable end is attached to a radio adaptor. A cable connects this radio to my TP-Link Archer C60 router. When ever I onnect my computer via a LAN from the back of the modem LAN port, internet connection (signal strength) turns yellow and red in a way that adobe connect becomes slow and I have difficuly hearing students' voice. The interesting thing is that when I connect my computer directly to the radio adaptor and not from the modem, there is a consistent connection and the signal strength is ful. I should mention that there is no problem with my modem, it is a brand new modem and I have the same problem with other modems too. I would be really grateful if you help me. My teaching success depends on your good help. 

Thank you.