@Phil_Claffey, It sounds like you are experiencing what is currently a fairly common issue; but maybe not... If so, though, an easy workaround may be in order for you.
I don't know if your update fixed your shutdown lag; but there are a half dozen risky commands to breeze past this annoying issue, as well as what you do: [quote="Phil_Claffey, post:1, topic:6388"]
I have to hold down the power button at the moment in order to turn it off.
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Whatever is causing it may never be found, e.g., systemd bugs, lagging daemons, programs that won't quit, or any number of other shutdown/reboot issues. But a good, safe, workaround (community link below) will help you forget about it. 