Slicer Sync Issues

The best way to solve this is to follow best practice and create dimension and fact tables aka star schema - see Microsoft Power BI best practice articles - https://learn.microsoft.com/en-us/power-bi/guidance/star-schema.

You have a Calendar table - this is a dimension table which should be joined (aka create relationship) to the other tables (facts) on the Date column (or Month column for Feedback fact table*). You need to mark it as a Date table. Make sure the dates start on Jan 1 and end on Dec 31, ie a complete year.

You need a separate Client table: one column with the names of all the clients. You can create this separately or use Power Query to do so (but might be a bit tricky with a number of different columns in fact tables). Load that into the model and then join that to the fact tables.

You mention Processes; but there are no Process columns in your image. If Process is a shared column then follow the same procedure as Client above and create a separate table and join it to the fact tables.

Once you have done so, then use the columns from the Dimension tables (Calendar, Client, Process) for row headers, column headers, slicers etc. Any filtering from these dimension tables automatically propagate to the fact tables. You can then easily sync between one page and another, or between visuals. 

*Feedback table: it's better if possible to add a Date column here rather than just have a Month column.

Hope that helps!