Excluded from non-profit discount

I have recently been trying to register a member of my team for Adobe Express free licence offer. We are a UK non-profit and appear to meet all the criteria set out in the terms and conditions. However, our application has been rejected by Goodstack several times, with the reason given that they are “unable to confirm your eligibility for the program”. Initially, we were told this was because the offer does not extend to mental health charities, which does not describe our organisation. After further discussion, Goodstack reclassified us as a drug and alcohol charity, but unfortunately this sector also appears to be excluded from the offer.

I cannot see anything on Adobe’s website suggesting that organisations are excluded based on generalised definition of their work. Is anyone able to clarify which charities are eligible for the discounts?