[Solved] Blockcerts.org verifier passed, Android app verifier failed

I issued a certificate on the bitcoin testnet, and it verified without a problem on blockcerts.org, but on the Android wallet app, it failed at step 1, saying:

Computed hash does not match expected hash. This test credential may have been altered. Please contact the issuer

any idea what might be the issue? Are the website and Android app using different hash functions?

Solved. Android app’s verifier rejects fake https certificate that I was using for my dev server