On the safety system indicators of the DB BR 425 the Sifa icon does not show, whether the Fuse is activated or not. This can result in a few Emergency Brake applications.
I think in this loco you had to stand up after enabling SIFA and sit back down for the game to register, which is obviously not 100% perfect but it should work this way.
No, I don't think so... If I remember, I will try it after work. I just remembered that there was/is a bug on HRR where wenn you activate the sifa switch while sitting down, you had to stand up and sit back down again or otherwise it won't show up on the hud. But maybe you have found a new, seperate issue...
I have mentioned this exact issue before: PlayStation - Db Br 425 No Sifa Warning On Hud In Tsw2 | Dovetail Games Forums It worked fine in TSW 2020, and only became an issue when it became part of the preserved collection in TSW2. I have also raised a ticket regarding this. I am hoping that when the preserved crew look at this route it will get looked into (fingers crossed)!
I too have already reported this in this forum in August last year. Hope TrainSim-Adam and his team can get this fixed at some point.