Hi John
Some time ago I had a similar error on my PC, randomly telling about problems with delayed writing to the HD. But it was not only while using BIAB. It went worse so I bought a new HD and cloned my HD to that. That annoying fault came back 2-3 weeks later! For test purpose I swapped the flat SATA cable between two of the HD’s in my PC - and I begun to get the same fault on the next drive!
A new SATA cable for 5 Euro solved my version of that problem.

Warm regards
Aulis G