Is my ASUS RT-AC5300 dying?

[Claghorn]

The ac class wireless works great, but I have more and more problems getting older devices that don't have ac to have reliable wifi connections. Should I try setting up separate SSIDs for different wifi bands instead of using it in the "you automagically figure it out" mode? Is there any kind of known bug this sounds like? (I have installed latest firmware).

 

[L&LD]

There are many flavors of 'latest firmware', which one specifically?

How many versions of hardware/firmware have you used the same SSID's? Separate SSID's for each band is essential to have control over where client devices connect and for general troubleshooting purposes.

When was the last time an M&M Config was performed on your router following the flashing of new firmware?

Please look in my signature below for the link to further details to get your hardware, firmware, and network devices to a good/known state.

Btw, I don't think it is a hardware failure of your router.

 

[Smokindog]

Separate SSID's for each band is essential to have control over where client devices connect and for general troubleshooting purposes.

Somewhat disagree - for years now most NICs have had the ability to set a preferred band. That said, for devices that don't support the feature, rather than have two separate SSIDs for main/daily use, one can temporarily set up a guest network per band for testing on most routers.

Btw, I don't think it is a hardware failure of your router.

Again, somewhat disagree - Never rule out the power bricks and the cheap design and manufacturing

When was the last time an M&M Config was performed on your router following the flashing of new firmware?

TOTALLY AGREE - sometimes you just need a clean slate!!!!

 

[L&LD]

@Smokindog, you are nitpicking here.

If I said 'full' control in my post, we're both right.

I don't rule out anything by default, but what the OP has described isn't a router issue (at this point), it's a client device and/or a configuration issue.