Tab S7+: mp4 on SD Card

Hey everyone,
I'm at a lost and need HELP lol

With my previous Tab A 10.5, I had no trouble transferring mp4 movies from my pc to the SD card.
Purchased the Tab S7+ last week, and its so weird and can't figure it out.

I transferred 15 mp4 movies from my pc to the SD card on my new tablet and only 3 of them plays. The 3 that plays, you can see the thumbnail with a photo, the rest are all a play button thumbnail. The black screen opens up like normal however, it stays black, the time shows 0:00:00, there's nothing.

If I take the same mp4 movie and transfer it to my Note 10+, no problem, it plays so I know there's nothing wrong with the file.

I'm not a newbie with technology, I just don't get it.

The SD Card is 1TB and brand new.
My preferred player is VLC but I also have MX Player.

What would be your suggestion/tip/trick?
Thanks,
Nat

 

Thats why I love this forum...lol...never even thought of swapping the cards and YES, when I swap, the movies that dont work on the tablet now work with the phone's card.

What the heck? SD card not good? Setting in the Tab S7+?

Maybe format the SD card and try to start over?

 

Sounds like a plan, that's what I'll do; start with formatting and if still doesn't work, return it and try a 'better' quality, maybe loosen up the purse and go for the Samsung Evo one...lol..I purchased a cheapy one (1024bg 30 bucks) lol

Thanks for your time, its truly appreciated....have a good night