Unfortunately, the issues with Nano X and its battery problems are already well documented both on this forum and social media, especially Reddit. It seems that only the first couple of batches they sold back when the device was relatively new operate as they should or at least as close to how they should. There are complaints with everything that came after.

I know that you wanted to fix the device yourself but by opening it up and manually working on it, you voided the warranty. Ledger will not take it back anymore. The right course of action would have been to first get in contact with their customer support and follow their recommendations. They would give you some instructions and ultimately send a replacement device if they determine the one you have is faulty. You can still contact them though to see what they will say.

Since you are looking to purchase another hardware wallet, consider some other brands as well. For instance, a Trezor or an airgapped HW like a Foundation Passport, Seedsigner or a Jade.