Time tracker with relational database problem?

i created a button in table A to add new row in table B with timestamp and check box to run time duration.
Uploading: 1643547248187.jpg…

in table B i make relation between column that when new row add with column A, relation data will also be linked to column B

Everything work fine if I take button formula for check box and timestamp out (as seen in picture two, when there is no timestamp, relation work fines)

Can you help me out? I’ve been messed up with this all day

Can you make the doc publicly viewable and copyable, and share the link here?

I already did @Nick_HE coda.io/@avanahotel/cmms