If you live in a suburb, there’s a good chance that throwing a new router at the problem is not going to fix the 2.4ghz issue.

There are only 3 usable channels on 2.4ghz. If you have a bunch of houses around you, it’s quite possible they are using up 2.4ghz. You can find this out by using a WiFi stumbler or spectrum analyzer to see how busy those 3 channels are.

Your money would probably be better invested on upgrading problematic devices to 5 ghz.