Does anyone know how to not have a date change daily so that a date created date can stay accurate online excel

Question

I'm running into the issue on online excel where my formula is printing 1/0/1900 as the date. I want my formula to print a date, created date. So essentially, the formula will respond to someone adding the status of the task as either open or complete, then the following column would print the current date and not change as more tasks are added on later dates.

=IF(H4 <> "", IF(I4 = "", NOW(),I4),"")

I tried changing it to today() instead of now() but same results. Not sure if anyone else has experienced this issue with excel online. The formula works fine on normal desktop excel, but for some reason not on online. I've also verified my time zone and that my calculation option is set to automatic.