Change this line:
if [[ "$TEST" == "ON Master" ]];
To this:
if [ "$TEST" == "ON Master" ];
Details
The issue is the use of [[ .. ]]. The output is showing you the difference. Your value that you're getting for $STATUS is not simply "On Master". It most likely contains other characters, that are most likely not printable so are not being seen.
[[ .. ]]
++ echo On Master
+ TEST='On Master'
+ [[ On Master == \O\N\ \M\a\s\t\e\r ]]
[ .. ]
++ echo On Master
+ TEST='On Master'
+ '[' 'On Master' == 'ON Master' ']'
The use of double square brackets ([[ .. ]]) is discussed here on the TLDP Advanced Bash Scripting pages.
echo $STATUS
This line seems a little suspicious to me as well. I'd protect the contents of $STATUS by wrapping it in double quotes as well.
TEST=`echo "$STATUS"`
Also I'd drop the back ticks (\..``) and use the $( ... ) notation instead for executing this command. This change is just a best practice and isn't part of your issue though.
TEST=$(echo "$STATUS")