GL-MT300A requires rebooting often

Hi, I really like this router but have problems with it not connecting with most devices after a couple days. It’s strange but I can always log into the router but I cannot print to any of my 3 wireless printers unless I reboot. They (and everything else) does not reply when I ping them or scan with Nmap. After a reboot all is fine and they show up and work and reply to pings but within another 48 hours or so, no more printing or pinging.
It’s weird but Roku and Amazon Echo still work. It is like something is going to sleep and only a reboot brings them back. All the devices show up in the client list but cannot scan them. What am I missing??? I hate to switch to a different router but my wife cannot always print when she needs to.

Thanks,
Bib

Does your printer have the ability to sleep?

Three different printers, I am sure they sleep but that has never been a problem. What the real problem is is that the router doesnt respond to nmap pings after roughly 48 hours or so. That is also when printers wont respond. If I reset router it is fine for another day or two. Its like the router is going to sleep.