Query editor not showing all columns in table

I have a table that contains multiple columns. For this example let's say it is a "personal details" table with expandable columns being first name, last name, email address, secondary email address, phone number.

When trying to expand my "personal details" table to include more than just partition key & row key, the only option that appears is column "last name". There should also be options to include the other columns in the table. They used to appear but have now disappeared!

Please help.