Probably one random issue, wanted to do first scenario of HRR whit 425, the sifa marker on normal HUD won't appear, made me unable to acknowledge it and have to turn it off, no warning sound in cab. Edit: same issue in other scenarios, this confirm that the sifa on 425 is broken in HRR scenarios
With HRR you have to stand up and sit down again after switching on the Sifa, otherwise it will not work properly. This bug has existed since the release of HRR and the old 425. EDIT: The Sifa marker in the HUD of the old 425 has never worked, so you have to manage without it.
