It's probably in the Windows Registry. I have seen this happen before, where there is a 'disconnect' between the Environment variable information, and the registry keys for the server. You can modify the registry settings to match the Environment variable, and you should be good. I have a sample that shows the keys to modify that can be modified or enhanced depending on what you are trying to do and is pretty straight-forward.
You can run a VBScript file on the machine that you want to modify. Paste the following code in Notepad, change the dummy license name (in this example replace all instances of ''TestServer'' with the actual license server you want to use, and save it as a .vbs file. You can then double-click on it to run it.
Const constHKEY_CURRENT_USER = &H80000001
Const constComputer = ''.''
Set objReg = GetObject(''winmgmts:{impersonationLevel=impersonate}!\'' &_
constComputer & ''rootdefault:StdRegProv'')
'Set Registry Settings for License Manager for QTP in Software Hive
strKeyPath = ''SoftwareMercury InteractiveLicense ManagerServerList''
strValueName = ''FT-Unified1.0''
strValue = ''TestServer''
objReg.SetStringValue constHKEY_CURRENT_USER, strKeyPath, strValueName, strValue
strKeyPath = ''SoftwareMercury InteractiveLicense ManagerServerList''
strValueName = ''FTAddins1.0''
strValue = ''TestServer''
objReg.SetStringValue constHKEY_CURRENT_USER, strKeyPath, strValueName, strValue
strKeyPath = ''SoftwareMercury InteractiveLicense ManagerServerList''
strValueName = ''AllServers''
strValue = ''TestServer''
objReg.SetStringValue constHKEY_CURRENT_USER, strKeyPath, strValueName, strValue
'Set the Environment variable to match the other keys
strKeyPath = ''Environment''
strValueName = ''LSFORCEHOST''
strValue = ''TestServer''
objReg.SetStringValue constHKEY_CURRENT_USER, strKeyPath, strValueName, strValue
Set objReg = Nothing
MsgBox ''QTP License Server information changed.''