(1) The department investigates each separation from insured work that occurred during the six weeks immediately preceding the effective date of an initial or an additional claim. The department shall adjudicate all separations that occurred during the six-week period except:

(a) when the claimant separates from both full-time and part-time employment in insured work, the department shall adjudicate only the separation from full-time employment; and

(b) when the claimant separates from insured work with the same employer more than once, the department shall adjudicate only the last separation involving that employer.

(2) If the claimant did not separate from insured work during the six-week period, the department shall investigate and adjudicate the claimant's most recent separation from insured work that occurred prior to the six weeks immediately preceding the effective date of the claim.