Git cert error for Win Store installed root cert

I have a FW inspecting SSL with own cert in front of Win10 machine running DW 21.0. So I imported the cert into Windows Cert Store under Trusted Root Certification/Certificates. But DW's Git access fails with "unable to get local issuer certificate" error.

After Googling some, I tried "git config --global http.sslBackend schannel" to add this globally in .gitconfig but still doesn't seem to look up the cert in the Window's store. Do I need to configure something in DW to make this work?

By the way, when I use Github Desktop to push the same file under local repo, it completes successfully.

Toshi