I am desperate

I have my old HP EliteBook 840 G3 with i5-6300U Skylake, HD520 graphics and 32GB of RAM. I wanted to install macOS to it, so I tried Sonoma. After some back and forth, I managed to boot the installer and install it. On the part when you have to select the macOS installer to complete the install, it would boot loop. ALWAYS. I tried multiple preconfigured EFI folders for my device, different model identifiers and followed dortania’s guide very closely. When trying it again with macOS Ventura, everything worked fine. My plan was to simply upgrade to macOS Sonoma afterwards. Simply. Spoiler: it wasn’t that easy. I tried everything I could think of. It showed me the update. But it always said it was unable to install. ALWAYS. AGAIN. I am very close to just throwing it out of the window. Please! Any help is GREATLY appreciated.