Here are the error messages I am seeing in access.log
1.2.3.4 - - [31/Jul/2019:10:07:58 +0530] "POST /connect/token HTTP/1.1" 400 80 "https://test.example.net/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36"
1.2.3.4 - - [31/Jul/2019:10:07:58 +0530] "POST /AdsvaluAPI/api/Authentication/UpdateLoginAttemptFailed HTTP/1.1" 201 132 "https://test.example.net/" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36"