Hi All. Hope this is a simple one. We have a 3cx system with 4 phones. 2 of the phones are the cheapo - Grandstream Budgetone 201 and the other 2 are Grandstream GXP 2100 Here’s the thing - I receive an incoming call and I answer on a Budgetone 201 extension I can transfer the call to another Budgetone 201 and/or I can transfer to a GXP2100 no problem. However if I receive the incoming call (or an internal call) on a GXP2100 I cannot transfer it to another phone - either a Budgetone 201 or a GXP2100. I can successfully place the call on hold on the GXP2100 and the other extension or caller can hear the music on hold and I can dial an extension, but it will not connect. Does anyone have any ideas here please? Thanks you Andy Keen.