H1 amendment with current employer and H1 processing with new employer

Hi all,

I started working for new client at new location, but my current employer did just LCA and not H1 amendment. He is planning to file it now.

I have got a new employment and my new employer has filed H1 in PP today.

If my current employer files H1 amendment now, is there any chance of it being rejected and will it affect H1 of new employer?

If my current employer files H1 amendment, is it still valid once I join new employer?

Will the amendment be completed and considered valid and in future when I apply for GC will there be no issue?