ESP32s3 UART/STDIO write delay when writing more than 128 bytes

[EvgenyG]

Hello
I'm using Micropython on a ESP32s3 4m processor
When writing messages longer than 128 bytes to the standard output the write appears to get stuck for a significant amount of time, around 10[ms] for every 128 bytes.
Adding a sleep for ~1.4 ms, which is roughly the time to write 128 bytes at 921600 baud rate, gets around the problem, however there is probably a cleaner solution
Is there a buffer whose size can be increased?
Thanks