Open the Data Register dialog of an investment, go in the "Prices" section, and leave it open.
Use a command in Edit menu > Investment Data > Update Price (or from the contextual menu of the investment) to update price(s) for the investment.
Issue: after the "Update Price" command execution the price(s) in the Data Register dialog is(are) not updated immediately. You have to close and reopen the Data Register for example to see the update(s).
---------------------
PS: there is another situation where the prices in the Data Register is not updated automatically: when you open two Data Register dialogs, one for an investment A and one for an investment B which is calculated from investment A. If you change/update prices in the Data Register for the investment A, the calculated prices in the Data Register of the investment B are not immediately refreshed. I'm not sure if this can be considered as an issue...