Bought a cheap truck sat nav from ebay, seller is mostly unhelpful surprise surprise.

The IGO software works on it fine but I wanted to use the Sygic software it has on in too.

When I go into the setting and try to change the vehicle height it will only allow changing the height to a lower height, put a height in greater than 14'9" and it just reverts back to 14'9".

Any ideas on how to solve this issue, is it a map issue i.e using the wrong map, or is it a setting in the software that wont allow it to be changed?

Thanks in advance for any light anyone can shed on this, a trial version on my phone allows the height to be adjusted higher than 14'9" no problem.

Oh yeah it's Sygic Fleet 10 that is on it.