When I connect my Global link 500 to the Victron 150/35 mppt controler , tracking becomes unstable and after a minute or less the power drops to 0 Watts, even in full sunshine. A minute or so later it recovers, starts tracking again only to repeat te same pattern after a short time. The global link works perfectly and I don't see anything wrong with the smartshunt either. When I disconnect the mppt from the global link tracking returns to its normal operation. Any ideas what this may be?