Has the wife been "helping out" when you aren't there?.....

I jest, it's either someone being less sympathetic to it than you, or your cloth has become contaminated with something abrasive. Could it have been dropped? Used for something else without you realising?

 

Yeah, it's been used to buff windows after cleaning. Thought I washed it out though.

 

As above, either the cloth has become contaminated (use fresh microfibre duster) Check for the ends of stitching in the cloth, the sharp ends of 'nylon' type thread's can be very sharp/ brittle

 

Get some microfiber cloths, use them for a while and then change them. Only use them for your machine. £5 for 4-10 pieces. Once contaminated there’s not much you can do. Don’t use them anymore for your machine.
For the scratches there not much you can do except for buffing it out with a compound etc. I did it once, but it’s a commitment, took me 1-2h of polishing, albeit it was quite scratched. Yours might be easier. I used this https://amzn.eu/d/fW0F0Qx

 

The arc pattern looks consistent, is that how you wipe it? To me if they were inflicted over a number of days they would be more random. Could it be from a ring on your or someone else's finger?

 

It is how I wipe it. I don't think it's my ring but I'll have to check my technique.

 

Get a towel not micro fibre cloth Whisper Soft Cloths (300 gsm)