Here is the full text of the phase one trade agreement: https://ustr.gov/sites/default/files/files/agreements/phase%20one%20agreement/Economic_And_Trade_Agreement_Between_The_United_States_And_China_Text.pdf

I think the right wing conspiracy theorists may be referring to clause 7.6 Section 2, which doesn't say anything about pandemic. It is much more harmless than any force majeure ("Act of God" you can't use with communists) clause in regular, boring commodity contracts that I have seen in 35 years in foreign trade business:

"In the event that a natural disaster or other unforeseeable event outside the control of the Parties delays a Party from timely complying with its obligations under this Agreement, the Parties shall consult with each other."

The core issue with all these allegations and conspiracy theories is, that nobody ever goes through the simple effort to google the relevant documentation and read the relevant parts.

Fascinating, how shallow and gullible people are, in believing twisted stories.