Loss of Contact "Groups" on iPhone after recent upgrade

I recently upgraded to iOS 14.2 on my iPhone 6S+, and since then I've noticed when I try to use my iCloud-stored Contact "Groups" in email, the titles of these groups are listed as available, but beneath each group it now says "No Members." These groups remain intact and accessible (containing all their members) when using the Mail app on my Mac; they're just suddenly MIA on my phone after always working fine before. Are others experiencing this? Is it already a known bug related to the new iOS—with a planned forthcoming fix, I hope? Or just some coincidental glitch with perhaps a different remedy?

Many thanks for your thoughts,

Jeff