Can an executor use estate funds to purchase/add property to the estate?

My father passed away a year ago, and he had a large assembly of properties that need to be sold and dispursed to 6 beneficiaries. The land is in a prime location for developers. However, the real estate agent noted that this land would be more valuable if they acquired an empty lot that is next to what the estate owns. The properties have rental income, so the executor took out a mortgage based on the rental income to purchase this lot for the estate. Now, the real estate agent is saying that the market is in a downturn, and this purchased lot is no longer making a difference pricewise.

Did the executor step out-of-bounds here? I have searched online and can't find any examples of where the executor increased the estate's real estate portfolio.