Temperatures below 0 celsius intesishome

I am discovering home assistant and was looking into using attributes. In doing so I ran across the outside_temperature attribute in the intesishome integration and quite easily managed to read this. However, the value on this sensor read 6548.6 whereas the temperature and setpoints returned correct values.

After some searching I found this topic. Not yet a definitive answer, but after some fiddling managed to get a seemingly correct value. The local website for intesishome returned temperature values multiplied by 10. Below the current sensor definition for outside temp. I know this will fail for positive temperatures, but first will monitor the negative ones this week and compare with values from weather platform (buienradar for me).

outside_temp:
  value_template: >-
    {{(0 - (65535 - (state_attr('climate.airco_1', 'outdoor_temp') * 10)) / 10}}

Curious to know wether others with an intesishome integration have the same issue and how they solved this (if solved). Since I am new on this forum, directions on how to post are welcome (categories, tags etc).