Oh, I did not think of the clients that have way.If you use an 'old' SSID, you may never see any issues. When your router otherwise seems to work as much as you can check the usual suspects, then using a new SSID with 8 characters and without any spaces, special characters, punctuation or smiley faces is almost the equivalent of 'resetting network settings' on all your devices and doing a reboot on them too.
The reason this works is that the router and the client device will negotiate what microcode to enable for the connection. If/when you upgrade/update the router to a newer firmware and/or different defaults as will happen with newer firmware, the client devices continue to use the old settings which the newly setup router may not support anymore, or worse, enable other settings than expected.
For any customer that I set up a router for, I make sure to do this so that I don't need to come back for random glitches related to non-sanitized network setup that may only save a few minutes of actual time vs. the alternative which can easily add up to hours or more.
I thought every time they connected they negotiated network settings (as it evens says so upon connecting from i.e. a mobile phone) and updated them accordningly.
And since the router is rebooted after doing all settings, the network connection needs to be reconnceted which I also thought meant renegotiated (and updated according to changes in router).
Im not a network expert, so I thank You for the feedback. I really did not think that network clients were that "stupid"