Context

Basic setup on the 1.20.1 Alpha Steam N Rails + Create 6.0.6:

1. Datapack to accept diesel from Create: Diesel Generators (UPD: doesn't matter. Works with lava too).
2. Fuel tank with diesel/lava inside + Portable Fuel Interface placed on train
3. Tested - Train drives
4. Set another Portable Fuel Interface outside of contraption
5. They are connected successfully
6. Run Mechanical Pump to pump diesel/lava from Fluid Tank to Portable Fuel Interface - crash

Crash happens right when two interfaces touch:

Crash Report

https://mclo.gs/Zh4afzj

Fixed by #644