saw cases that LPR was granted even though the applicant had changed more than 3 jobs.
It all depends on the DAO who processes ur case. If RFE is sent, tax return(w-2) may be requested. If the DAO thought u can't switch job, u might encounter problems.
If u have a lawyer, he/she could have straighted it out for u as long as he/she is familiar with portability allowed by USCIS and act in ur best interest.