Filter list shows correct ref result count, but not the related rows

[HSAI]

I have created a list field with a formula in one table, to filter results from a second table if some values in the second table, match the row in the first one.  What i'm finding is it shows the correct result count, but it's not showing the related rows. Has anyone else had this problem? 

As shown below, on the first table, there are 3 results (which is correct), however the results themselves are not displaying: 

I am using IF, FILTER & AND because there are multiple filter criteria, and two versions of the filter depending one of the variables of the first table:

IF(AND([METHOD]<>"Lookup",[METHOD]<>"Calc"),FILTER("Tasks",AND(([SET_MEASURE]=[_THISROW].[MEASURE]),([SET_EXPRESSION]=[_THISROW].[EXPRESSION]),([SET_METHOD]=[_THISROW].[METHOD]),([SET_LOCATION]=[_THISROW].[LOCATION]),([AGED_DAYS]<=[_THISROW].[AGE_MAX_DAYS]),([AGGREGATE_DAYS]=[_THISROW].[AGGREGATE_DAYS]),([SET_INDUSTRY]=[_THISROW].[INDUSTRY]),([SET]<>[_THISROW].[ID]))),FILTER("Tasks",AND(([SET_MEASURE]=[_THISROW].[MEASURE]),([SET_EXPRESSION]=[_THISROW].[EXPRESSION]),([SET_LOCATION]=[_THISROW].[LOCATION]),([AGED_DAYS]<=[_THISROW].[AGE_MAX_DAYS]),([AGGREGATE_DAYS]=[_THISROW].[AGGREGATE_DAYS]),([SET_INDUSTRY]=[_THISROW].[INDUSTRY]),([SET]<>[_THISROW].[ID]))))

Thank you

[Marc_Dillon]

This is often due to a mis-match between the 2 tables referenced as indicated below:

[HSAI]

Hi Marc, Thanks for the suggestion. I've taken a look but unfortunately I don't think this is it - mine are both the same table: "Tasks"