Hi @AlanTellez,
You are right. The order you have defined in the Jira select list custom field configuration is not retained once imported in eazyBI.
I recommend defining a new calculated member in the Mes dimension. There, within the Aggregate() function, reference the dimension members in the order you want them to appear in the page selection. Please see a post from the community site Tips&tricks category for more details - How to change order of columns and rows in the report?.
Also, visit the eazyBI documentation page for details on defining calculated members in other dimensions - Calculated measures and members.
Best,
Roberts // support@eazybi.com