Finding identifier whose given value is smallest

Hello

I need your help for a simple issue I cannot solve... I have a table, named TBL below, that contains columns PR, FA and Prio. I need to create a new column RPR with content equivalent to ExpectedPR column below. It gives for set of PR with same FA the one which has lowest Prio

RPR1 below is giving in front of PR the Priority but what I need is PR id whose value is lowest

RPR1 = CALCULATE(
    MIN([Prio]),
    FILTER(TBL,TBL[FA]=EARLIEST([FA]))
)

I tried several trials using TOPN, FIRSTNONBLANK, CALCULATE, SUMMARIZE,... but I am not able to find the correct formula. Any idea?

Below just to load the example

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WCjBU0lFycwSRRkAcYKQUqxMNomCihkiixlhFTcCiIB0g+QBTiKgpXNQIKhoLAA==", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [PR = _t, FA = _t, Prio = _t, ExpectedPR = _t])
in
    Source

Thanks for your help!