The grass hanging off the transducer is probably not helping
I am by no means an expert but here is maybe something you might try, seeing as how a normal battery voltage is 12.6ish and yours shows 13.1 that tells me you have your fishfinder hooked up to the cranking battery. Maybe try to hook it up on its own battery and see if anything changes.
Also your transducer does not look like the XHS 9 HDSI 180. From the google searches I find for that it comes up with the newer longer and thinner transducer.