lr mobile export blury

Hallo, I'am using LR Mobile on an Android Tablet since quite some time. I always export the images to my blog with 1140px (wide side). This way the image is displayed at 100% on the website and always was as sharp as expected.

Some weeks ago the tablet broke down. With the new tablet (lenovo legion tab) an LR v9.2.2 the export at 1140px are very soft, means not usable. The exportsettings are, jpg 1140px width 90% quality, sharpening for sceen standard, sRGB. To achive an aceptable result I have to export the images with much bigger with much more pixel then I need, what makes my blog slow.

Attached are the rawfile, a fullsize export and an export at 1140px with.

Am I doing something wrong, how can I solve this problem?

Thanks for any help, Hannes