I have a desktop hardwired to the Gateway, which is 4G, presently. Around 4PM the download data rate drops from 50 mbps to 2~4 mbps. Initially, I tried the usual cmd lines, release, renew, flushdns... no speed change. The next morning, bingo... 50 mbps. Same issue that afternoon. I called Verizon support and they finally rebooted the system and the download speed returned to 50 mbps. I asked if there was a soft reset that I could issue. Otherwise, I have to push the reset button on the underside of the unit, which is a pain. They told me to look in the manual, which I have done. I told them that if it was there, it was hidden. There is no reboot command for this unit, but they can reboot it remotely. So, I figured that one exists somewhere.
Finally, it dawned on me to backup and restore the unit. While the unit was downloading at 50 mbps, I backed up the settings. Tonight (3/4/2022), the download speed went to 3 mbps. I restored the unit and it reported that it was REBOOTing. The speed went back up to 50 mbps. Success.