Power fx formula column no longer support calculating currency in another related table

The column in above table was created before and suddenly some time this feature is removed. Before this happened, the formula column works fine, and then after the changes, you cannot modify or create new formula column that is using reference to related entity's currency column. This basically broke my app as I really need to try modifying the logic for calculation.
An alternative is to switch back to calculated column, it's like back to 5 years ago.
Anyone know what's going on?