Excel not recognizing field headers

Over the last couple weeks I've been having a common issue with Excel not recognizing that my fields have headers. I just opened a .csv file (have had it happen with .xlsx as well) and went to add filters with ctrl+shift+L and it put it on the second row. Okay, I remove them, select first row and do it again. Then I selected a column and used a quick sort and my headers got shuffled. Alright, I undo it and click the sort button and check the box to say my fields have headers. Then I throw the data into a pivot table and it defaults to the second row, so I had to change the data source to grab the top row.

This has been happening more frequently recently. Has anyone else experienced this? Is there something that causes this to happen or anything I can do to prevent it moving forward? It's not a huge hassle but it is annoying to constantly have to reestablish the top row as headers.