Have seen this several times when customers (eventually) explained that they have moved the machine for one reason or another.
They don’t think twice about tipping them back at odd angles and then the above happening.
Have done the hairdryer trick as above and have had ne recalls.
Another thing I’ve seen is where the back panel is against the (now redundant) vent hole through the wall. In cold weather condensation will form on the inside off the panel and water gathers.