I bought an iMac27 refurbished (Apple) early Jan2021--initially had no problems with wifi (had moved up from iMac21)--it came loaded with Big Sur--in last 3 months it has been slipping off my very strong router (in our apt--private) and going onto the public, much slower wifi---it doesn't seem to want to hold to initial connection and choses , on its own, to go looking for another connection--
iMac 27″, macOS 11.4
you can start here: Use Wireless Diagnostics on Mac
and also look here: Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support
you can start here: Use Wireless Diagnostics on Mac
and also look here: Resolve Wi-Fi and Bluetooth issues caused by wireless interference - Apple Support
to further explain--I live in a bldg with 88 apts--we all have a separate internet connection we pay for with a private router in our apt--my iMac27 can see about 20-25 routers--some of which are ones supplied by mgmt and some are CenturyLink--upon running Wifi Diagnostics the app picked out one centuryLink router which it says has a UK country code--don't know yet how far away it is--but I also went to Sys Prefs->Network->Wifi->Advanced and in first tab is list of all routers I've ever been connected with on my MBPro which I travel with--in the right column I unselected "Auto-Join" for all except my private router including "SP Public" which the iMac27 kept slipping into---(I also deleted all other past wifi connections) -maybe that will solve this problem--not sure how I'd solve problem of Country code--
so, if the iMac keeps connecting to the unwanted wifi, is the iMac close enough to your personal router to connect it via ethernet cable? if it is, you can disable the iMac's wifi at the iMac end while leaving your wifi active for the MBP.
One point regarding Other Router broadcasting as UK Code - that is a Router originally destined for the UK Market or the ISP that made it available for usage in the USA , did not care and leave it that way. That or the users are not savvy enough to get into the Router Software and switch it to CA - Canada -.
Example - I live in a Condo in Toronto and like yourself 45 - 50 other routers around. Some are personal Router and some are supplied by ISPs. That said, one ISP ( un-named here ) imports there Routers from USA and broadcasts as USA. This really messes with the Canada CA Code and thus interfere with my connection until I put Tin Foil in certain places to Block their Signal.
Wall to wall Floor to Ceiling Bookcase on one wall - The entire back of bookcase with Tin foil. Opposite wall - several 3 ft x 3 ft Framed Pictures all with Tin Foil. Juts enough to disrupt the External Wifi signals and make my Internal Wifi less bombarded with undesired signals. Alcan is very good to me - purchased when on sale.
here's the basics: Share your printer on Mac - Apple Support
if you need a step by step: How to Print to a Printer Connected to Another Mac Computer
Is the iMac close enough to your router that you can connect it via Ethernet? If so you would be best served to connect via Ethernet as it's faster and more reliable than WiFi.
OMG! Is this your room?
😉
i can't believe i missed that the first time. iMac YES, ethernet is a much better option for the mac if possible.
ok--I could put a 6-9 ft ethernet cable from iMac to router box under desk---but how would wife's MBPro see my system from other end of apt to use my printer which is wired to iMac27?--
this is helpful--could you possibly explain where you put the tin foil?
Yup ;-)
big sur wifi problems
