Zscaler root certificate make TEAMs File share working

Hello All,

Our user faced issues accessing TEAMs files/uploading any files over TEAMs chat.
We investigated and at last it was resolved by adding Zscaler root certificate in user’s trusted store(Intermediate certification authority and Trusted root certification) which was missing out there. However, I want to know how adding Zscaler root certificate resolved the issue though my APP profile already have bypassed settings applied for TEAMs traffic( from app profile’s dropbox to bypass selected application). NOTE: Sharepoint also started working after importing cert which was giving issues earlier.
Please clarify!