Hello,
yesterday when checking a FP with Eurocontrol for validation I encountered an odd behaviour.
Route EDDL/05R N0385F240 MODR6Z MODRU Z283 LNO LNO5A EBBR/25L, the FP to be copied into the IFPUV had -and has- a different FL than the one I put in.
As you can see in pic 1 the filed FL is 160 and this gives an error because the MODR6Z Sid has an exit at or above FL210. After correcting this error the result is ok.
The second odd is that when you generate the very same FP to get the OFP and the FLs are correct, see pic 2.
So it seems that SimBrief takes the Estimated Altitude of the Route Finder (that in this case was 16000, not depicted in pics), even if it is not activated.
All the best.