Battery Stick Up Cam Motion Sensing

I recently moved an indoor battery powered stick-up cam (that has always worked correctly) from inside the house to inside a garage window that looks out over the entire grounds at the north side of the house. The intent is to detect and give us awareness of bears in that area using motion sensing. We have a lot of bears in the yard this year. I set up one motion detection zone that adequately covers the necessary area. But no motion is being detected. Not even with the sensitivity setting slid to max. Tested this with humans and large dogs walking through the area. I don’t need alarms or sirens just a motion notification on iPhone Ring app. The cam is 12 feet above the ground looking out through a clean single pane window. The cam is set right up against the window with maybe 1 inch separation. The max slant range I want detection at is about 100 feet. Min range is about 15 feet. Signal strength is low at -81 worst case (it varies better at times) but all other camera attributes work fine including live view. What am I doing wrong. Is it the window that prevents motion detection? Is the zone too big?Is signal strength too low for motion detection? If signal strength is the problem is there a recommended wifi extender for this camera?