When I upload images to the chrome web store as promotional images (appears to work fine for small tiles large and marquee sizes) they become unreasonably blurry. As they give two options (1280x800 size or 640x400 size) i have tried both but to no avail. For example:
Original image as a png and with size 1280x800:

After uploading and submitted:

I discovered that the 640x400 size works slightly better than the 1280x80 (no idea why) but it is still unreasonably blurry. This is the highest quality photoshop can export, and I tried creating it in adobe XD - same issue.
For reference this is the 1280x800 blurriness

Any ideas as to how I can fix this? Because it looks really bad and quite unprofessional.