Update: I’ve emailed Namebright support with the details above and a request to forward to their Director of Software Development. The support staff said they’d forwarded it, but so far I haven’t gotten a reply.
In the meantime, @sahsanu has written a detailed guide for Namebright customers on how to change your authoritative DNS to Cloudflare. Following this guide for your domain will fix the CAA SERVFAIL for you and allow you to issue again: Guide to change DNS servers from NameBright to CloudFlare.