That moment when the trouble you've been trying to chase down with the release with dnsmasq 2.90 in this firmware. The random performance ones, and the partial page/site loads. Where you have, to an extent, correlated it to a restart of dnsmasq log that you've seen in the log that happened at the same time the problems happen. But you could never capture it, because it would seemingly happen randomly, and only for a short time, and occur on random devices.
When all of a sudden you remember that scMerlin lets you restart dnsmasq easily, with the click of a mouse, on demand
The issues I was reporting with dnsmasq. That I was starting to tie to the restart of it. That manifested when going to a site/page that partially loads, or seemed slow post the restart. Well, the perfermance eventually returns, and pages/sites now load load fine as dnsmasq settles down from the reload (hence randomness ant the short duration of the issues).
Even the first time a page/site is accessed after a reload, or a random page/site is loaded for the first time, no longer happens and performance returns after dnsmasq and router settles down from the reload.
Firefox set to use DoH/DNSSEC with Cloudflare never saw the problems. All browsers (Chrome, Edge, Firefox, Safari, an so on) tested did, regardless of device, DOT configured on the router or not, with WAN DNS set to Cloudflare/Google/others did, on every dnsmaq restart until the router settled down from the reload of dnsmasq.
I can't capture the details in the system log, it doesn't show up. Didn't really didn't see it in TOP/HTOP either.
But I can replicate the effect on demand, hopefully others can and will be able to as well.
Once dnsmasq is running, if a reload isn't triggered again, and the router stays up and running, after things settle down. Performance returns, lookups succeed, pages/sites load fine.
The problems have gone away haven't resurfaced (but haven't had a random event causing dnsmasq restart either)
Hopefully the fixes
@RMerlin talks about in post #96 and others running this release of firmware, don't report any other related issues, to get us to another release soon.