Dear Katie.
Good day!!
I understand your concern, considering that this issue is related to sort and filter a Gallery in PowerApps, I would like to suggest you post your concern in the dedicated channel Microsoft PowerApps Community. We are sure that our experts from that team can address your query effectively and accurately.
The reason I ask you to post a new thread is that in Microsoft Community, we have limited resources and very little knowledge about PowerApps queries, and in Microsoft PowerApps Community you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction.
Appreciate your patience and understanding and thank you for your time and cooperation.
Sincerely,
Tina | Microsoft Community Moderator