We have a custom, single line text field used to record an identifier. This identifier should always be unique and we have some automation set up which will notify the reporter via email if an identifier is reused. We have found when the identifier starts with "NO", the automation is triggered and an email sent. I tested it out as a search and found it matches similar identifiers starting with other letters.

I get the same result even when no identifiers start with "NO". i.e. while "NO-XX-02" does not exist, it will still match "MJ-XX-02". I do not see the issue when using other letter combinations. So searching for "MJ-XX-01" does not return "NO-XX-01". Tested with a general text search too and see the exact same issue.
Does anyone know why this might be happening? Is NO being treated as an operator in some way?