Sat nav on my 2016my is that bad that I can’t help thinking the settings may be wrong?

Set it to come back from Holyhead to Manchester yesterday and all was fine till I got about 20 miles down the a55 on the mainland. For some reason at this point it spent about 10 miles trying to divert me onto the A5. This is a slow road at best would have added about 40 miles to the trip, not to mention the extra time it would have taken.

It spent about 10 miles trying to get me to do a u turn, before eventually giving in and being right for the rest of the journey. This isn’t a massive problem when I know roughly where I’m going, but an absolute sod when I’m lost. It’s at the point now that I don’t trust it at all and have to set the phone as well. Im pretty sure it was set to fastest route so my question is; is there another setting cocking it up?

As a MY16 I don’t think i’ll Ever get the CarPlay option to use waze or google maps? Range Rover Sport HSE DYnamic SDV6 Velocity blue 2020 MY
Range Rover sport HSE Dynamic P400e Silver
Range Rover Sport 3.0 SDV6 HSE Dynamic 2016 MY
Range Rover sport 3.6tdv8HSE 2007 Gone
Range Rover sport 2.7tdv6SE 2005 Gone
Range Rover sport 2.7tdv6SE 2007 honey
Range rover Vogue 2005 4.4 - GONE and missed
BMW 535d M sport 2006 - GONE not as missed
BMW X5 4.4 2004 sport - GONE

it could be the re-routing is activated by the tmc traffic diversions...switch this off and all will be ok..