You should probably be running your renewal pipeline more frequently than that: if you had let your ACME client set itself up on a single server, it would probably run every 12h for a 90-day certificate. The ACME client won't actually give you a new certificate until the old one is old enough to be worth renewing, and you have many more opportunities to notice that the pipeline isn't doing what you expect than if you only run when you expect to receive a new certificate.