I experienced a similar sounding issue, but was able to decipher the blocked emerge output from portage to find that app-crypt/tpm2-tss-engine was blocking the

I experienced a similar sounding issue, but was able to decipher the blocked emerge output from portage to find that app-crypt/tpm2-tss-engine was blocking the whole system from getting onto openssl-3. Once I dropped tpm2-tss-engine, things went forward swimmingly. No other unmasking/masking of anything was needed.