I have my FF400 since a long time, amazing from RME to still support this interface with new updates!

I am having trouble though, suddenly my computers can´t connect, red host light is always on.
My setup is Macbook Pro late 2018, I connect through the 3 adapters (fw400->800> thunderbolt 2 > thunderbolt 3). It worked perfectly until recently, I didn´t change anything on my computer, still on macOS Mojave 10.14.6
I´ve tried going directly into the Macbook Pro, via a CalDigit TS3 Plus Dock (this worked perfectly with low latency).
I´ve also dug out my old Macbook Pro (I think 2012 model) with the Firewire 800 connector, no luck. Red host light.
I have tried two different firewire400 > 800 cables, that have worked perfectly in the past.
I´ve reinstalled RME drivers on both Computers.
Tried it with power supply and without (on the old computer with direct Firewire connection), no luck.

Is there something else I could try?

I´d hate to think it is broken and has to be discarded..

I do have the new Babyface Pro as well, but I´d like to continue using the Fireface400 in the studio...

Thanks for your help!