Not sure this will help but check your ini db settings. This is from 6.7 but the settings in 7.5 are similar...
IdleDB=0
SLimDB=0
HLimDB=0
KeepDB=0
MinDB=0
IdleXXX is the number of seconds to allow a connection to be idle
before automatically disconnecting. 0 to disable this feature.
SLimXXX is a soft (advisory) limit. This number can be exceeded at
peak load, but this tries to limit the number of idle connections.
Limits are only checked when opening a connection, so it is possible
to have > number of idle connections. XXX is adapter type, using the
same notation used on a command line. Ex: MQS is MQSeries, etc.
HLimXXX is a hard (mandatory) limit. This number will not be exceeded.
Connections will be placed in a pending state rather than exceed this
number.
MinXXX is a minimum number of connections to keep. When a limit (SLim
or HLim) is exceeded, idle connections will be removed until no more
than Min remain (if possible).
KeepXXX is how long (in seconds) an idle connection is expected to
remain valid. Connections idle longer than this will be tested prior
to being used (if the adapter supports it). If the test fails or is
not supported, the connection will not be reused. A value of 0 disables
this feature. A value of -1 will force a test every time, but this is
not recommended.