Qlik sense forecast on a line chart

[ZimaBlue]

Hello!

I'm trying to use a forecast in qlik sense on a line chart. There are many dimensions in the source data, such as 'sources', 'advertising campaigns', and so on.

Now the problem is that the forecast is displayed only when there are no filters. If I select a filter by any dimension, then I see only the dates that have already passed, and the forecast for the future disappears.

the dimension is the dates, and the measure is the number of users

I am also not very satisfied with the forecast results, which are more similar to the average for previous periods. Can I get a forecast with slightly larger fluctuations?

I use:

LinEst_B(total aggr(if(sum(f_user_id_Mcount),sum(f_user_id_Mcount)),f_rank),f_rank)+
LinEst_M(total aggr(if(Sum(f_user_id_Mcount),sum(f_user_id_Mcount)),f_rank),f_rank)*f_rank

where f_user_id_Mcount is number of users and f_rank is the rank for each day, set using autonumber()

Dates are sorted in ascending order, but they can be repeated since I use multiple dimensions (columns).