Hi, my personal Wi-Fi tells me that it’s a “Weak Security “ I have used this Wi-Fi for years and it never said it was weak security before. How can I fix this?

See the Apple Support article(s) below.

Wi-Fi routers and access points - Recommended settings for

I have posted elsewhere on this topic so I will keep it short. After a recent update to my iMac using Big Sur, my Mac showed my wifi had 'weak security'. My iPhone had similar warnings. I contacted Virgin Media, my ISP, who took me through updating my hub to more secure settings. This was not difficult. My iPhone no longer shows wifi security warnings but my iMac does.

Network settings on my iMac show that the stronger security settings in my hub WPA2-PSK[AES] are not shown in my iMac which still shows WPA/WPA2 PERSONAL. I have contacted Apple Support, switch of the iMac, unplugged and switch on again to no effect. I have caused my iMac to 'forget' existing networks and re-established them to no effect.

I have been advised that I could Reset NVRAM or PRAM on my iMac but, for me, this is a bridge too far. I have had assurances from my ISP that my network is secure after updating the security settings in my hub; and my iPhone no longer shows wifi security warnings. I think my iMac is giving a false warning based on old security information which its software has not updated.