Investors & landlords

I'm invested through a Schwab brokerage, and they have told me they will submit my K-1 forms and have already filed an Extension Request on my behalf because they are still collecting information from the issuer.  This is a new experience; they claim it's due to a change in the tax law for 2020 returns.  Does anyone else have this situation?  I've already submitted my return with my two K-1 forms as they were sent to me.  I'm not getting much clear info from Schwab or my broker.