Computer signals with ATEM SDI Pro ISO and HD Studio HD Plus

I have a couple of HyperDeck Studio HD Plus and just got a ATEM SDI Pro ISO.

ATEM set up for 1920x1080 25p.

Notices an issue that on several different laptop signals;
- Hyperdecks seems to process a laptop HDMI great
- SDI out from the hyperdecks is not processed by the ATEM, input shows up as black screen.
(Multiview out works great but that input that should be showing the computer is black)

Funnily enough it works with some settings on laptop out, like 1920x1080 50p, but not 1920x1080 25p.

Also done a couple of tests where I forward the SDI out to another hyperdeck, which understands the signal. It only seems to the ATEM having issues with the Laptop the problem manifests.

Is there any recommended approach? For example, is there any way to force the hyperdeck to always output to provide a more ATEM friendly signal, regardless of if the laptop provides a weird signal?

I could try to put a cross converter or some other box in-between later, but is there some "obvious" HyperDeck setting I ought to try first?

Test setup 1
Laptop ->
Blackmagic Design HyperDeck Studio HD Plus ->
Blackmagic ATEM SDI Pro ISO ->
SmartView 4K

All cabling (except the laptop, which is HDMI) is SDI with pretty decent 4K compliant cables and terminators, overkill for 1080, so I do not really think the cables are the issue

Works:
Laptop 1920x1080 50: image on hyperdeck, image on Atem.

Does not work:
Laptop 1920x1080 25: image on hyperdeck, no image on Atem.
Laptop 1920x1080 60: image on hyperdeck, no image on Atem.


Test setup 2
Canon C300 ->
Blackmagic Design HyperDeck Studio HD Plus ->
Blackmagic ATEM SDI Pro ISO ->
SmartView 4K

Works:
Canon C300 1920x1080 25p: image on hyperdeck, image on Atem.
Canon C300 1920x1080 50i: image on hyperdeck, image on Atem.