Thank you for reaching out. I can certainly understand your concern with not being able to crop your screenshots and I would be happy to look into this further for you. Are you trying to crop from the screenshot screen or the Gallery?
I would recommend testing your device in safe mode to see if you still experience these symptoms. If your phone or tablet is misbehaving, it's possible that a third-party app is causing the issue. To figure out what app is acting funny, you can use the Safe mode feature. In Safe mode, your device won't run any third-party apps. Give this link a try to test your device in safe mode: https://www.samsung.com/us/support/answer/ANS00062983/
Next step would be to wipe the cache partition on your device.
The system cache partition stores temporary system data. It's supposed to allow the system to access apps more quickly and efficiently, but sometimes things get cluttered and outdated, so a periodic cache clearing can help make the system run more smoothly. Give these steps a try:
Step 1: Turn off the phone. Step 2: Press and hold the Volume Up key and the Side/Power key. Step 3: When the Samsung Galaxy logo appears, release both the Volume Up key and Side/Power key. You will see the ‘Installing system update’ message appearing briefly before the Android Recovery menu options shows up. Step 4: Press the Volume down key several times to highlight Wipe cache partition option.
Step 5: Once the wipe cache partition option is highlighted, press the Side/Power key to select. Step 6: Press the Volume down key to highlight Yes, then press the Side/Power key to select. Step 7: When the process is complete, Reboot system now is highlighted.
Step 8: Press the Side/Power key to restart the phone.
