Can you try this version please and let me know if you are still seeing unwanted browser windows:
http://downloads.iwascoding.com/downloads/GarageSale_7_2017-10-18.dmg
http://downloads.iwascoding.com/downloads/GarageSale_7_2017-10-23_1.dmg
If so, please note the date and time when this happened. This way it it’s easier to find the right entry in the logs.