If the recount cannot be completed due to the lockdown the Secretary of State either cannot certify the election results or certifies the results without a recount the legislature needs to declare the certification invalid and proceed from there.
If the recount cannot be completed due to the lockdown, the Secretary of State either cannot certify the election results or may certify the results without a recount. In such a case, the Michigan legislature needs to declare the certification invalid and proceed from there.
Consider as well the work the Trump team is doing to uncover election fraud in the state.