Help with a Bedrock Template Issue for My Job

I'm currently working as a technology trainee, and it's my first job while I'm still in school, so I'm learning a lot on the go! I've been assigned a project where I use a template called Claude Haiku 3 to extract info from specific documents. Recently, I've encountered a problem: while this template used to work perfectly, now it sometimes fails by providing missing or incorrect data. The template is supposed to gather information like Social Security Numbers (SSNs) and Employer Identification Numbers (EINs), but it sometimes invents data when it can't find the relevant details. Often, it'll give me the SSN when there should be an EIN instead, which can lead to some serious accuracy issues. I'm not sure if the problem can be fixed by adjusting the prompt or if I need to switch to a different template, like Haiku 3.5, since I can't afford more expensive options. Any advice would be hugely appreciated!