help for opendtu best configuration for HM 1500 and b2500

[ghino18]

hi have an HM 1500 inverter and a b2500 marsetek battery.
Actually on both of the two MTPP i connected a panel and one of the output of the b2500 .
The system seems works but i have a problem with the surplus function of the b2500 battery.
If i enable it the battery start to feed the inverter on both output but after a while they stop.
If i disable surplus and enable manually , they start again for a while then stop.
Is some configuration that i have to change can do to mantain surplus feed active ?