Data issue when filtering in PQ

[Walt1010]

In the Power Query editor, all the date fields show dates, until I filter by one of the staff names, in which case the dates all show as errors. Any ideas why that would be the case? 

[Akash_Varuna · Accepted solution]

Hi @Walt1010 Could you check for any of these issues 

• Check Data Types:
  Ensure the date column is set to Date type. Mixed types can cause errors.

• Inspect Filtered Rows:
  Remove the filter and check rows for invalid or blank values in the date column.

• Replace Errors:

  • Use Replace Errors to replace invalid values with null.
  • Or, use Remove Errors to exclude problematic rows.

• Review Query Steps:
  Check APPLIED STEPS for transformations that might corrupt the date column.
  If this post helped please do give a kudos and accept this as a solution 
  Thanks In Advance