@seventeen As suggested by terziyski, you can try to connect the two by Ethernet cable, then check if the connection will be improved.

@Guy01 What is the region version of the RE450? Is it US version also? If the RE300 is an EU version, it might be that the 5G wireless channel on the C7 is not compatible with it, you can try to...

@Yuvalyitz @NNguy As you can see it proves to be the cable issue by the OP, so we hope you could confirm this first. You can try with a different cat6 or cat7 cable between the switches on both side,...

@CDB Sorry to know that. When referring to "the kext", does it mean the printer controller utility? Is it running automatically when the computer starts up? What if you disable the auto-run, will the...

@WilliamTS You may reset the router to factory defaults manually again, reconfigure it from scratch to connect to the internet again, then monitor if the issue will happen again. Do pay attention to...

@FreakXL Hello, what is the model number of the old router? Is the AX73 LAN connected to its WAN or LAN? Ensure its WAN/LAN do support 1000Mbps Full duplex. What if you connect the AX73 LAN to a...