I just got a new BE24000 (aka Archer BE900) today. I have 300 Mbps up/down Verizon FiOS internet with Ethernet. I had Verizon's router and thought I'd improve things by getting this BE24000 but so far across the board, upload performance is way worse. My phone that used to easily get higher than 300/300 now manages 300 Mbps down but only about 120 Mbps up. My M4 MacBook Air is doing even worse, more like 240/80. I haven't tested the performance of other devices yet. 
 

I am on the latest firmware. I also set up an MLO network to see if that would help but it doesn't. My iPhone 17 Pro actually gets a little worse performance than the above on that network. 
 

I know if I call Verizon they will say it's not their router so they can't help. Does anyone here use this router with FiOS and get good upload performance?