Have same issue on my MacBook Pro 13 2017 non Touch Bar. When unplug charger laptop just shut down. Made clean install of High Sierra and updated to Catalina and don't see any warning about battery replacement. But coconut still says that it's capacity only 68%. Don't know should I upgrade to big sur again.

Guys I never checked my battery with coconut and don't know my battery capacity before Big Sur. But after I updated I have 3h sot maximum and coconut says that it's only 68% capacity (210 cycles). On Big Sur I have "Service Recommended" icon but on Catalina never seen this. Don't even know should I replace battery or it's Big Sur bug MacBook Pro 13 2017 non Touch Bar