Video Assist 5.0 Level A / B SDI

Hi,
I am new to the forum and try to use it in the right way. Sorry, if I misstep, and thanks for help.
I have a Video Assist 5 Screen and realized a new thing:
If I feed the screen via HDMI with 1080p60 or 1080p50 from my Laptop the SDI Output is Level B
If I feed it with 1080p25 there is no Level sign (I check this with a Decimator MD-HX cross converter).
If I check the Signal (HDMI input to Decimator directly from Laptop (a Dell latitude)), it says 3G-A 1080p60.
If I feed the video assist with 1080p60 3G-A it shows the picture AND outputs 3G-A 1080p60.

I didn't know that HDMI has these Levels as well. Am I correct?
In a post here i found that most / all BMD devices go with SDI Level B.
There seems to be no chance to change a setting in my Video Assist?
What could I use to change that? of course a decimator, but that is quite expensive for that work i think.

I came to that while testing a Lumantek ez-SHV+ Scaler. this accepts no B Level. I wanted to use it as a very simple SDI Tester because it shows an SDI Eye Pattern.

Thanks for help, advice, thoughts and hints.
sk

It’s only 3G SDI signals (50-60p) that are level A or B. For 1.5G and 4K signals there is no A/B level.

Good Luck