Preview not playing at all

Hello,

In Ppro CC 2018, I imported 4 footage that are

.mp4 files with :

about 85Mb/s data rate

29.97 fps

audio at 48.000 KHz

Once imported I couldn't get them played in my preview window, nor in the main sequence, it just wouldn't play. The play icon would turn as if it would play but nothing happens. Very frustrating... it makes the program useless...

I tried many tweaks there and there from recent posts that seem to have almost the same problem but nothing fixed it... I had to install the CC 2017 version... which comes with problems, especially the dynamic links with inserted AE comps (like lower thirds), which I had to render on the side and import in... Huge loss of time... I spent 4 hours on the fixing that failed, and some more time to get Ppro 2017 installed and get those AE comps rendered and imported. My wholde day schedule got delayed... and I started to drown...

Good I do not have tons of ongoing projects that I started with Ppro CC 2018... otherwise I would just be completely sinking into abyss, dragged down by my clients' complaints...

Adobe, you got to fix this... lots of other bugs are happening... sudden freezes, random long opening times for simple projects, rendering freezes when done within Ppro and not with Media Encoder...

Here are my computer specs

Threadripper 1950x

32Go of RAM

Win 10 Pro (set for performance)

Radeon Vega 56 (updated)

I allocated 11Go of RAM to Adobe apps (AE, Ppro, Photoshop, I don't use other apps).

Thanks for your quickest help !

Jy