dnsmasq issue

[mwhaples]

Hello, I wasn't quite sure where to post this, its a Asus firmware issue but it could lead into selecting new equipment. I am having issues with dnsmasq on my Asus ZenWiFi BT10. Every week or two devices on my network start having connection issues, both wired and wireless. By connection issue I mean DNS lookups start failing, when connecting new devices IP addresses are not being assigned, etc. Additionally in the log at the time of the issue I will see messages like:

Feb 24 13:05:37 dnsmasq[5902]: failed to send packet: Bad file descriptor

I have contacted Asus support. Their suggestion was to try turning off most things, from IPv6 to AI Protect, adaptive QOS, etc or to try other firmware versions. The only thing I have not turned off which they suggested is IPv6, it should be a fairly core feature by now. turning things off isn't really a solution as I bought Asus stuff understanding it could do all these things and so if I must turn them off then I may as well have bought something else, may be cheaper. As for other firmwares, I am using the current one which was put out this month and before that the previous version. from a security point of view do I want to be using even older firmware?
I also have been through the reset the entire system and rebuild the config from scratch, no restoring from backups, but I still get the issue.
I would appreciate some advice on how to get a stable network. Here are some thoughts of mine:

1. Anything else I can do to diagnose the issue? Its though feeling like a lost cause and would still need a fix working out, if at all possible. Is it time to move to other options.
2. Have something else do DHCP on my network, may it be a wired router with the Asus stuff as wifi access points or use my home server to host a DHCP server.
3. Replace the Asus stuff. Whilst in the past Asus stuff has served me well and when it works the current setup does the job well, this issue has really knocked my positive view of Asus routers. My concern here though being might I spend a lot of money and find the new stuff has equal issues.

I am probably favouring option 2, probably with a wired router for simplicity (can I be bothered to learn how to set up DHCP servers on Debian on my server). It may be the balance between quick and simple and keeping costs down, although I am not taken by the thought of yet another network box in the lounge.