Auto Refresh Gateway issue

Hi Expert,

I have a Pro subscription. I have 100 reports which refreshes on daily basis. All are connected to SQL server. I have applied timeout period to 500 while connecting SQL through Import mode for all 100 reports. Most of reports have millions of records.

Out of which 25 reports are using total 7 SQL Views out of which 4 Views are common in each 25 report( have applied brand filter on power query) and other 3 views are different for each report. These 25 reports never gets refreshed successfully. When I refresh from desktop all 7 views are refreshes at same time and I can see the proper number of each view but for 2 views (Huge data, separate view) It gets timeout error. Because of that all other views refresh gets failed. Whenever PBI report refreshes so all 7 views are start refreshing. It creates lot of Mashup containers on Server, It never release resources on server even when reports fail. I have to manually reset the gateway to kill the mashup containers. because of too much of Mashup containers report never get resources. When I reset the gateway, few reports run successfully but after 4-5 reports, again too much mashup containers and other reports are getting failed. 
I have to individually refresh each 7 views for single report from desktop which is not feasible solution. Schedule time for 25 report from 8am to 4pm.

Can somebody explain me why failure of refresh happening for every report?

Why too much Mashup containers always there on server even when reports are not refreshing?

Any help or suggestion would be helpful. Looking forward for your help.

Thanks!