I'm pretty sure that wouldn't work because the UF 7.1 driver was compiled with the 12.1 client.
The Oracle compatibility matrix states 12.1 client will work up to 19c - as long as you don't want
to make use of any new features after 12.1.
I''ve faced the same predicament here - so we're sitting on 12.1 client when we move to 19c this fall.
HTH - Knut