Hi @ofirbo ,
Thank you for your interest in the NXP MIMXRT product, I would like to provide service for you.
When you download the code and debug the code in the flash, do you also can make the function works?
In fact, I suggest you to use MX25UM51345GXDI00 instead of MX25UM51245GXDI00 , these two chips have the data swap difference:

You can see, the MX25UM51245GXDI00 data is: D1、D0、D3、D2... sequence, it is not like MX25UM51345GXDI00, that's why you have the boot issues.
If you use MX25UM51345GXDI00 ,you can refer to my post:
https://community.nxp.com/t5/i-MX-RT-Knowledge-Base/RT1170-Octal-flash-enablement/ta-p/1498369
If must need to use MX25UM51245GXDI00, you need to do the flashloader dataswap, you can refer to this blog:
https://www.cnblogs.com/henjay724/p/15880374.html
As it is the Chinese document, but you can use the translation tool to read it, this is from the nxp internal expert, very useful to you.
Wish it helps you!
If you still have question about it, please kindly let me know.
Best Regards,
Kerry