PBI Report Server Log size increasing fast

PBI Report Server log getting full so fast.
I have Power BI Report server Jan 2019 release. I have upgraded from Aug-2018 release to Jan-2019 release. PBI Report server log is getting filled by 1GB everyday in Jan-2019 release which was not the case in Aug-2018 release.
I have 14 PBI Reports having data refresh scheduler running every hour. What might be reason? Is it duw to less refresh interval? What is option to limit it to 5 gb max? Currently Log size is increased upto 25 gb hence I am unable to upload updated Report becasue of log issue.

Appreciate your help.