Do not share timesheets and other PebblePad templates with your mentor (practice assessor / practice supervisor).
If you shared your timesheets, you have done the wrong type of share and that is why your mentor cannot write in the boxes or tick any tick boxes.
Only share your PebblePad WORKBOOK, MYePAD (nursing), eMORA (midwifery) for example.
Your timesheets, or other templates, will be located inside your workbook, and that is where your mentor needs to access them.
1) Unshare your templates from the information side panel in your assets.
2) Share your workbook, making sure you're choosing 'share with an external', not 'share with people'.
The correct type of share will show in the information side panel of your assets, under external assessors. Make sure you have shared your workbook, so your mentor can access your timesheets from within the workbook. Always set an expiry date when you share.