Agilex 5 premium board - es version - boots with gibberish prompts

Hello Fawaz,

Thank you for taking care.

My answers below, in a Question-And-Answer manner:
Q: Does the terminal show the same behavior every time you run? Like clean text outputs then garbled?
A: Yes

Q: Your exact PuTTY serial settings: baud rate, data bits, stop bits, parity, and especially flow control ( a snapshot would be good to have).
A: Attached (20260428124741agilex5premium_es_putty_config.jpg)

Q: Which COM port you're connected to and how many show up in Device Manager when the board is plugged in.
A: When the board is plugged in, I see only one com port, (as opposed to your expectation above of having 2), COM10. It vanishes when I unplug the board.
     For mutual convenience, attached is a screenshot (20260428125702agilex5premium_es_com_port.jpg)

Q: How many gibberish transitions you see? is it one clean-to-garbled switch, or does it happen more than once across the boot sequence?
A: As far as I inspected the prompts, it is one clean-to-garbled switch

Q: Another suggestion worth trying: If you can catch the U-Boot prompt (spam a key during SPL to interrupt autoboot), run printenv baudrate and printenv bootargs and send the output; that would tell us about what the later stages are expecting.
A: I tried spamming a key during the SPL prompts, but failed to stopped the transition to gibberish prompts.