Ssrs multi parameter issue

I have multi value parameters in Report 1 in report 2 i also have the same 6 parameters.
Both reports have values. example in REPORT 1 PARAM county has lake, palm, broward as choices REPORT 2 has the same lake, palm, broward as optionts.

REPORT one is linked to REPORT two using the column labeled Loction which is hyperlinked on Report 1, so once clicked it brings the user to REPORT 2.

if the user selects multiple, or single values for REPORT 1 and click on Location, those values actually are been passed to REPORT 2 PARAM County, however if i try to change the param values from REPORT 2, whenever i do this it is defaulting to the values that were passed from report 1. Im using =SPLIT(JOIN(Param.value,","(,",") to pass values from Report 1 to 2, Can some one assist