I want to lock/protect certain range of cells in a row if a checkbox in that row is ticked

I have a google sheet --> LINK ( https://docs.google.com/spreadsheets/d/10T_bctLC_QjYEbQlSt_M9RsaWigaT0WqM5hDUCr3BHg/edit?usp=sharing ) I have 2 tabs named Sheet1 and Sheet2. In Sheet1 the users enter their details and put tick mark in column F. Once the user ticks, i want that row including that checkbox to be un-editable by the user but me (owner) can still edit it. Similarly in Sheet2 also i need the same functionality when tick is made. I also require a timestamp when tick mark is made. I tried using data validation (custom formula is =$F2=FALSE) to lock cells but the drop down list just disapperaed . I also used a script along with this called 'WriteOnceReadMany' to track on column F and lock it once it is ticked. If i used only the script then the cells are locking immediately even before the tick mark. So in what way can i accomplish this either with formula or script.

Please help me accomplish in locking that particular row when check box in column F of that row is ticked in sheet1. and in sheet2 it should be locked when student tick it. Do suggest me, thank you. View question