Size animation glitch

Hi please help me with the size animation, I’m using size animation to open and close the vertical nav menu. It’s working but at the start of the animation, there is a kind of glitch or something.

Here is the read-only link, I’m new to the community, SO please support as soon as possible.

https://preview.webflow.com/preview/emrich-dashboard?utm_medium=preview_link&utm_source=designer&utm_content=emrich-dashboard&preview=7c23ff75281016b185a370962c13b8fa&mode=preview