T46G BLF functionality not as expected

[Yealink Support]

Hi Martin，
Oh, so you want the phone to dial out 140*1 directly?
You are making a group pickup?
If yes, you can access to the phone webpage-Features-Call pickup
Then enabled group pickup, and fill the pickup code, as the attachment.
When there's incoming call on your monitor number, you can pickup the handset, and press Gpickup softkey to pickup the call.
Our V71 firmware is different from privious firmware.
You mentioned that T2X and T3X works well, i think you are using V60 or V61 firmware, if you upgrade to V70/V71 firmware, the behavior will the same as T46G.
Any misunderstanding please let us know, thanks.