Oil pressure control red flashing/peeping

Good day, my car has been playing the following game with me for months: At higher outside temperatures above 20 degrees I drive an everyday distance of about 30km highway at a speedy pace (150). As soon as I then leave the highway and brake on city speed shortly afterwards the red oil lamp starts to blink inclusive. Last time the oil pump was renewed and the said phenomenon stayed out about a month. But now again today. Now my question, someone had the gleic he problem like me and has found the causer? The car now has 78,000km down and it is the 1.2l 69Ps machine