I have two tables, a Shell table, and an item table as follows

Shell Table |
|||
---|---|---|---|

Column 1 | Column 2 | Column 3 | Column 4 |

A | null | random value | random value |

B | random value | random value | random value |

C | random value | random value | random value |

Item Table |
|||

Column 1 | Column 5 | Column 6 | Column 7 |

A | A1 | random value | random value |

A | A2 | random value | random value |

A | A3 | random value | random value |

B | B1 | random value | random value |

B | B2 | random value | random value |

B | B3 | random value | random value |

C | C1 | random value | random value |

C | C2 | random value | random value |

C | C3 | random value | random value |

I set up actions so that whenever I click on any of the rows, the other table will adjust so that only the related rows are showing up. For example, when clicking on the second row on the shell table (B), I will see only the B rows on the item table. This works exactly as we would expect.

My problem starts whenever I try to click on the first row on the shell table. by clicking on A, nothing shows on the item table even though there are 3 rows that should show up. However, when clicking on any of the A values on the item table, the shell table filters to show only the A row. This means that the filtering is only working in one direction for the A related rows. All the other rows work perfectly and filter both ways.

The problem stops happening when removing column 2 on the shell table which has a null value for row A. Whenever this column is removed and there is no longer a null, the tables filter properly.

Why is this happening? Is this a glitch in the system? why is the filtering only working one way when there is a null present?