I really don't want to believe this.... but it worked for me (so far on my pc monitor) I really thought I tried both ports, but i didn't try it with the samsung sd-card, maybe that did the trick??
I'm going to try (a bit ashamed haha) it on my regular TV.
Sometimes the solution is so simple, you forget to try the most simple things...
Yes, my freezes at the same spot, hdmi cec. My other sd I tried was a sandisk but without result.
I tried on my pc monitor and on my 2019 samsung smart tv without any luck. I will keep looking for solutions but so far I can't find any.
I have the exact same problem, tried different sd cards en I use the original rpi power adapter AND hdmi cable. Everything is brand new (except sdcard, wich is an samsung evo 32gb class 10 uhs 1) and did a clean install. I'm not new to libre elec or rpi, had it working on the pi3 but wanted to test the benefits of the pi 4 (4K).
One time i've gotten trough the freeze but couldn't play anything, on reboot it freezed again 
I got myself the rpi with 2gb of ram.
