So I sold my Beta SE skimmer and bought this new Surfer S2 (I'm on my 2nd unit because the first S2's's right propeller motor failed in less than 120hrs of run time, but at least it was before Amazon's 30 day return period was over). I also have the Aiper Scuba S1 as well which is awesome.While this Surfer S2 works very, very well when dry, as soon as it sprinkles even a little rain, I get warning messages on my phone that "one of the sensors may be blocked" and the unit just spins in tight circles forcing me to take it out of the pool. This happened to my first unit that died and now with my second unit as well and it's very frustrating.I emailed Aiper telling them my issue in hopes that they can issue a firmware update to somehow fix this as it is a pretty big issue, but I only received a reply from their AI bot which was no help at all.I will update this review when and if there is something to update.UPDATE:After the interaction with the AI bot (and before this review went live) a real person from Aiper reached out to me and we chatted back and forth over a few day span and they asked me to do several things like check the firmware, give them my order number, current shipping address and the unit's serial number which I did and in the end, they said that the unit should not be used in the rain.They also said that the algorithm is that the unit should 'self correct' itself from the spinning attitude back to normal function once it stops raining and the water dries from the sensor lenses. I have yet to give this a try as I have always removed the unit once I see the spinning but will leave it in the pool during the next rain session and see what happens.UPDATE 2: (Performance Review)The performance of this unit in the dry is simply amazing. It runs 24/7 and the lowest I've ever seen the battery is 51% and that was right before sunrise.The surface cleaning is simply on another level and the debris guard system works as advertised and nothing escapes while the unit stops, turns around and backs up. The wall edge cleaning works as described as well and from what I can tell, it will hug the wall of the pool for a complete lap about once every 3hrs.The surface of my water looks almost "polished" and it is awesome! It's nice going to bed on a windy night knowing that the little robot is on the job and whatever blows in will be picked up before my alarm goes off.The online app is pretty sparse, but it's fine and tells you how many total hours the unit has been in the pool, as well as how many hours and minutes the current clean cycle has been running. It shows air temp, battery level and unit info like firmware, serial number and ip address.Dry weather: Perfection!Rain: Not so muchUPDATE3:Aiper's customer service has reached out to me several times and has confirmed that with the help of my feedback they are working on a new firmware update that will vastly improve rainy weather performance and that update should be pushed out sometime in April 2025.I have changed my rating from 3 stars to 5 stars due to the dry weather performance, plus the incredible customer support that I have received and the quick attention to fixing the issue.