Tonight on my way home I noticed a line running fron top to bottom on my tft screen?

Has anyone else had this problem or is my screen dying?

is it permanent or does it sometimes disappear?

The connections to the glass are normally done by conductive rubber pads that are clamped or taped to the glass, I assume Land Rover do the same. You may find (if you're brave enough) reseating the glass would cure the problem on the other hand it may never work again. I would try applying pressure to the top and bottom around where the line is, it disappears you know the issue if it doesn't prepare to spend some money. BMW i3 Electric Car
2012 Full Fat RR 4.4 TDV8 (now gone)
2006 VW Touareg 3.0 TDi V6

Last night was the first time I’d seen it so hoping it’s gone this morning but I’ll let you no. Current: 16 my2016 Range Rover l405 4.4 sdv8 Aruba gold & 11 MY2011 RANGE ROVER L322 4.4 TDV8 ZERMATT SILVER

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59 MY2010 Range Rover Vogue L322 3.6 TDV8 Zermatt Silver
53 Range Rover Vogue L322 4.4 V8 Java Black
98 P38 Range Rover 2.5 DSE Champagne Gold