Well, hi everyone!

So I recently needed to reinstall the OS on my PC. I had MXLinux installed previously and knew that it worked well, but I felt like I wanted to go with something more traditional this time and downloaded a Debian ISO. First attempt with small ISO: boots to black screen with blinking cursor in the top left corner.
Second attempt with large ISO: same result.
Then I tried the live DVD ISO - wont even boot.
Ok, so it must be a driver issue then, I thought and voila - the non-free live ISO booted and installed just fine.
However, after restarting, I got a "no bootable device found" error.
I reinstalled it again, thinking something might have gone wrong during grub installation, but no luck.
If I use MBR instead of GPT and choose EFI, I get to the encryption password prompt, where I enter the correct password and then get a "no such cryptodisk" error.

After some time, I just gave up and installed MX, which installed and worked right away. It is a little frustrating though. I am not a professional, but I wouldn't say I am a Linux noob at all (I use Arch on my Laptop).
I would actually really like to use Debian again, because I haven't in years.

I suspect that the issue has either to do with some GRUB/UEFI thing or some driver thing with my GPU (AMD Radeon).
I searched the web extensively to find an answer, but none of the things I found online helped.
So if somebody could provide me with a hint or help me to get this fixed that would be awesome. I will provide further data as needed.

Thanks everyone and have a nice day!

I had similar issues on my very old (Dell) laptop.
MX 19 (KDE) installed like a breeze. Debian gave me headache. Also install disks with non-free drivers aboard. Even no luck with the brand new Siduction.
I looked at one of the main differences between MX and pure Debian: systemd (MX does without by default), but could not track it down to that. After install, MX worked OK with systemd as well...
I like MX a lot, especially for the easy creation of the live installable ISO and the ease of installing in a LUKS encrypted FS. But the upgrade path worries me. MX18 --> MX19 required a reinstall. At my desktop I'm very happy with Debian Sid. Would love to run that on my laptop as well...
<frustration>I tried several more ways. E.g., I created a running Debian on a USB drive, with Timeshift. It boots on a lot of machines, but not on my laptop.</frustration>
So I will follow this discussion with special interest.

Check your 'uefi/bios' data, I had to disable something or other to allow booting on a laptop that came with Windows installed - may be part of the problem - another may be the size of your dos partition, & whether you set the right boot parameters.

Since you re-installed MX, get some information this time on the hardware specs and what kernel drivers MX is using that Debian might not because of the non-free thing or similar. The command: lspci -v might give us some information to help you get it installed.
Just set BIOS/FIRMWARE settings to UEFI without Secure Boot for now, and disable fast boot if the option is available. Debian pretty much installs properly on any supported UEFI systems and will give two kernel options, one for Secure Boot where out of tree drivers will need be signed and the other will evade this hassle with Secure Boot disabled.
But in any case, please provide hardware specs, otherwise it just sounds like venting.