Linkedin Company Image Post - Text is cropped at 300 characters

Hey there. I’m stuck in this for a few days and wondering if anyone figured it out.

My goal is simply to post on a LinkedIn Company page (via API), an Image post with a text description that is over 300 characters.

I’ve been in down rabit holes with the IMAGE API (new method) and UGC Posts (apparently older method). I can’t make it happen!

Does anyone know how to do this? Thank you