You can't show a break in employment when claiming your Employment Expenses. You need to make sure you only enter expenses which fall within the dates shown on your T2200 (and have them available if CRA requests to see them and the T2200). If you are claiming vehicle expenses, still use your kms for the entire year as the total driven in the year, and only the amounts for employment purposes you have recorded that fall within those dates.
https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-re...