Changing employer at the time of filing I-485

I’ve approved PERM 8089 and I-140 from my current employer. I’m about to file I-485 with this current employer in EB3 category as the filing date just got current for me(PD 2013).
Now, I’ve got job offer from new employer which agree to provide Attorney to file my I-485 with USCIS and cover all legal fees. My job duties, description going to remain same.
1.Is it okay to change employment when I’m about to file form I-485 first time with USCIS per AC-21 act?
2.Attorney mentioned I don’t need to file I-140 again as its approved for 180 days and beyond, is it true(I’m concerned as I didn’t come across similar situation discussed through any blogs)?

Once you change employers, you have to file a new PERM and new I-140, there is no getting around that I think but I maybe wrong

Thanks Nimit! This helps.

Any other confirm opinions?

Its recommended to stay with current employer who is filing your i485 for at least 180 days.