The controllers made this year function differently, they have an onboard microprocessor and the display functions have changed. The green light blink is the five second count down to running the pump, your old one did the same thing, but did not blink, however it also required the water measure low for 5 seconds before turning on the pump, we just now have a visual indicator that pumping is about to start.
New optic sensors have always been very prone to interference, it is a brand new piece of plastic, plastic repels water and attracts air, this is the same reason a new skimmer does not work well. It must be seasoned through a few days of use and this can be accelerated by a hot soapy water rinse. The sensor only detects air vs water so a clinging bubble gives the same result as being dry. Your old one would have had the same issue when it was new and this usually subsides after 3-7 days, or a hot soapy water rinse, provided it is in a relatively calm and bubble free area.