I connect to a fiber modem over pppoe and my internet speed is 140Mbps.

when i reboot the moded and I test internet speed it shows 140Mbps download and 80 Mbps upload, later in the week (say thursday) i start noticing my youutube stream on my phone starts pausing, so i go to my laptop and do speed test and it shows max of 5Mbps. once i reboot it goes back to 140Mbps.

This is new since i bought tis router 3 months ago.

-Waleed