I once had a check for about $900, drawn from a home equity line with tens of thousands available, rejected at a camera store by the Chex system which the store

I once had a check for about $900, drawn from a home equity line with tens of thousands available, rejected at a camera store by the Chex system which the store used at POS. There was no recourse that I could find despite spending quite a bit of effort trying. This was many years ago but remains a mystery as my credit was, and remains, great.