It would appear the "life insurance policy" is using its own earnings (interest, dividends) to pay renewal premiums; when these earnings are withdrawn from the account, the distribution is taxable.
Your description of this account indicates it has some invested assets - it is not just a "life insurance policy" or "a sum of money". Without specifics on the nature of this account (investment?), it would be impossible to give you an exact answer as to why you are receiving a taxable distribution.
You still have a "basis" in the value of the account. That would be the amount included (and taxed) in your 2019 W-2. It will become a factor in calculating taxable income when you start taking distributions from the "principal" balance of the account.
