Payment Assistant delaying payments to large vendors

We recently started using Payment Assistant as well and thus far I am unimpressed. Payments to utility companies especially are taking significantly longer to be processed and are not reaching their designated vendors in time resulting in late fees. When I reach out for customer support I am told to simply stop the payment and reissue it, which doesn't actually save me any time. Our designated representative is helpful and left me feeling hopeful but the escalations she has put through have thus far not brought any results. Generally payments to smaller vendors who have more direct customer service lines are paid quickly, but electric, gas, and water bills especially are not getting paid. My guess is that because there is no billing specific service representative that REPAY is unable to get ahold of anyone to receive payment preferences and checks are just being sent out, but they do not seem to be arriving to their destinations. Has anyone else had this problem and how have you gotten around it? Thank you