There is an amount limit, but it can vary based on the location (according to your agreement with Paynet) you plan on using to complete the transaction. Depending on the location, the max amount limits can be one of the following: 5,000 MXN, 10,000 MXN, 15,000 MXN and 29,999 MXN.
Flywire will cap it at the highest maximum amount. Below you can find the current limits set by location, or you may verify through paynet.com.mx.