I have a custom function that accepts three range names as input parameters. When values of cells in these ranges change, the function output stays the same. This is a "feature" of the platform.
Is there any proper way (as of yet) to make custom functions in Google Sheets recalculate dynamically? I know people have tried adding now() as a parameter, which used to continuously recalculate regardless of need. (Now blocked in new sheets.) Has anyone found a satisfactory solution?
The proper way to make a custom function recalculate is to change an argument of it. Regarding the use of NOW() and other similar built-in functions as arguments of custom functions, from Custom functions in Google Sheets:
Custom function arguments must be deterministic. That is, built-in spreadsheet functions that return a different result each time they calculate — such as NOW() or RAND() — are not allowed as arguments to a custom function. If a custom function tries to return a value based on one of these volatile built-in function, it will display Loading... indefinitely.
From a comment by Mogsdad to this answer:
In fact, rather than "Loading...", this will display an
#ERROR!, This function is not allowed to reference a cell with NOW(), RAND(), or RANDBETWEEN()