The choice of 2.4 GHz for wifi was a pretty bad one in hindsights. The same band can interfere with cordless phones (that's why I only buy DECT 6.0 phones myself), Bluetooth, microwave ovens... That's why the industry is slowly shifting to the 5 GHz band, which will resolve a lot of interference issues.
Asuswrt-Merlin: Customized firmware for Asus routers
Github: github.com/RMerl - Twitter: RMerlinDev
See the sticky post for more info.