The problem is magento migrated tool complete with migrate setting data. Normally the migration tool re-encrypts settings, but it’s easy to miss that for custom modules.
If this isn’t done, your setting(s) will still have weaker legacy encryption from M1, which M2 rejects when you try to install a new module that references them.
You can either fix your migration tool configuration and remigrate, or remove the legacy encrypted values from core_config_data table.
You can find affected settings after migration with a query like:
SELECT * FROM core_config_data WHERE value LIKE '0:2:%'
Then Remove all records with query result.