Spent the last few days monitoring log file backups. The file size is different each time with much larger sizes during working hours and much smaller size during off-peak hours. This is what I would expect to see.
So I'm not seeing an issue at this point. Yet I have no explanation for why the log file was 120gb last week. Almost sounds as if I'm dealing with an application issue not closing a transaction like it should.
I adjusted the autogrowth settings. I'll continue to monitor weekly and report back here if I see an issue. Thanks for the response, sorry to waste your time.