I have an Asus AC5300 and it has worked great for years. Today I updated Merlin firmware to version 386.3.2 Immediately after update was complete I checked and my internet speed has slowed to about 300 Mbps. I was getting 930 Mbps before the update. I've checked QOS is all disabled, and can't seem to find out why it is being limited. I checked the speed immediately before I upgraded ( 930 Mbps) and once the upgrade was complete (300 Mbps). This has done this multiple times. I reinstall the older version it goes back to normal. It slows with all versions after 384.5.0. Any help would be greatly appreciated.