Many thanks for the clue @golla!
That helps :-)
And there is a new version of MicroMDM released last week with the fix required
https://github.com/micromdm/micromdm/releases/tag/v1.8.0
[Update MDM Vendor CSR signing to SHA-2 and use new Apple intermediate cert (#723, #725)]
RavikanthBollapragada
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