I just got a Fuji X-T20 2 days ago and I have some problems 
first of all my battery takes a full day to charge which is very odd 
secondly every time i record 4K it says “write error” however I did insert a old memory card on it with only 17mb writing speed, it works fine with 1080 recording but the problem only occurs when I record 4K. So I ordered a sanDisk extreme pro 32Gb with a 90mb writing speed and it will arrive in 3 days. 
so can the problem be due to the old memory card or should I just return the camera and get a refund?

Got an xt20 this year. Also besides the 18-55 kit lens I have purchased a 27mm, a 10-24mm, a 55-140. I just purchased a Lee filter kit with Big and Little stopper. Live in the Smoky Mountain area, so lots of good landscapes to photograph. Question. I understand I need to block light from coming through the view finder when using the filters. How do I do that, put it on LCD only?

Has anyone encountered an issue where after attaching or changing a lens and turning the camera on the screen flickers like shown on this video I recorded earlier?
I have tried cleaning the contact pins on the camera and the lens but the issue still persists. The lenses I have are the 23mm 1.4 and the 18-55 kit lens. There is no issue when turning on the camera without a lens or when using a manual lens without contact pins. The flickering also happens randomly, sometimes attaching a lens produces no issue, sometimes it does. I don't know what causes it.
Any information would be greatly appreciated. Thanks!

I recently got an XT20 with the 18-55 kit lens. Today I was trying it out at home, when I found out that when I try to zoom quickly in or out in manual mode, I see a horizontal light appear for a fraction of a second on the EVF. I cannot see this happening on the LCD. This happens only in manual mode, and not auto. This does not happen when recording a video. I am using mechanical shutter. But I don't think this is a shutter issue as I see this white line for a second when zooming quickly. Also I don't see it when I see EVF auto brightness from Auto to manual. The firmware is updated. Also tried zooming outside, I don't see that issue.
The issue is as described here by another user:
 

Article on Lens Review - 7Artisans 60mm F2.8 1:1 Macro with Fuji X-T30 camera.
Image samples on 7Artisans 60mm F2.8 lens Flickr group.
Article on disassembly, focus calibration of 7Artisans 60mm F2.8 lens