They have different bootloader bl1 and adjusted u-boot to support 2G memory. If you don't have 2G of memory or memory has some different configuration, which is extremely unlikely, than this can make troubles. The rest is the same. I know that T3+ image doesn't boot on 1G boards (M3 for example).
Your board looks the same, but I did a picture to double check.
How do you power the board? I use lab PSU 5V / 5A
Running low on ideas. This is serial console log - try to catch something on yours: