Anyone who accepts credit cards is assigned a 'category' (called an MCC code). All of Eleyo's payment processing is assigned a code for Schools. Some issuers or providers of Flexible Spending Accounts (FSA) will only allow transactions coded as Child Care to be authorized when a payment is attempted. There is no option for Eleyo to change how the payment processing is coded.
If a transaction is declined, it is not the Eleyo system that is declining it or that the Eleyo system can or can not accept FSA, but rather what the issuer or provider is allowing or not allowing. Some parents report success contacting the provider and explaining the situation (i.e. that the charges are for child care). They may be granted an exception by the provider to allow the transactions to be approved. Every issuer is different so it is up to the customer to discuss it with their issuer and see if they will allow these transactions to be approved.
In some cases, parents have been told that Eleyo is not an approved vendor. One possible explanation for that is the FSA provider has a more narrow group of codes that it considers 'approved'. Another is that some FSAs are set up when the user has to accrue funds to then be applied to child care (i.e. on a weekly or bi-weekly basis). If a particular transaction is denied, it could be due to lack of funds to apply specifically to the child care portion of the FSA. This again would be something that the parent would need to discuss with their specific provider.