Why are many fields not responding to the formula?

Question

Google Sheets

I have a table and several columns, in the formula column, if the value of the start date is empty, then the end date is also empty, however this does not work

Answer 1

Your cells are not empty, the data in them - visually empty - is generated by formulas, according to your comment to the question. In such cases, ISBLANK returns FALSE.
Solutions:
- set the date manually (it's rather strange to generate the date of issuance of something by a formula, it must be a hard-coded value)
- change the formula for the date of withdrawal - check not the emptyness of the "date of issue" cell, but, for example, the length of the text in it.

Answer 2