Cannot forward any calls

I have Asterisk+DPMA configured with about of 40 Digium IP phones.
Everything works fine, except one thing:
When i try to forward incoming call without picking up a handset i got “Not accepting call completion offers from call-forward recipient” notice in asterisk cli.
Forwarding call to other user if call is answered already works without a problem.

I found and read a bunch of themes i found one most suitable comment
Can't find where extension is forwarded, but i can’t find the necessary option in phone configuration.

can_forward_calls=yes
is enabled for all Digium phones

My situation is:
User 5310 calling to user 5173, user 5173 clicks forward softkey and enters 6010 as number to farward call to.
the last line with -- Executing [5310@short_number_calls:4] is a step which is caused if 5173 doesn’t answers the call

Call log of this situation:

    -- Executing [5310@call_out:1] Log("SIP/6010-0000010f", "NOTICE, |28012019-15:26:39|-|1548681999.454|-|"6010" <6010>, 5310| "6010" <6010> calling with extension= 5310") in new stack
[Jan 28 15:26:39] NOTICE[8399][C-0000008b]: Ext. 5310:1 @ call_out:  |28012019-15:26:39|-|1548681999.454|-|"6010" <6010>, 5310| "6010" <6010> calling with extension= 5310
    -- Executing [5310@call_out:2] Set("SIP/6010-0000010f", "GLOBAL(call_number)=5310") in new stack
  == Setting global variable 'call_number' to '5310'
    -- Executing [5310@call_out:3] GotoIf("SIP/6010-0000010f", "0?call_from_preset_gateway,5310,1") in new stack
    -- Executing [5310@call_out:4] GotoIf("SIP/6010-0000010f", "1?short_number_calls,5310,1") in new stack
    -- Goto (short_number_calls,5310,1)
    -- Executing [5310@short_number_calls:1] Log("SIP/6010-0000010f", "NOTICE, |28012019-15:26:39|-|1548681999.454|-|"6010" <6010>, 5310| Internal call from "6010" <6010> to 5310. Dial Status of 5310: OK (1 ms)") in new stack
[Jan 28 15:26:39] NOTICE[8399][C-0000008b]: Ext. 5310:1 @ short_number_calls:  |28012019-15:26:39|-|1548681999.454|-|"6010" <6010>, 5310| Internal call from "6010" <6010> to 5310. Dial Status of 5310: OK (1 ms)
    -- Executing [5310@short_number_calls:2] Set("SIP/6010-0000010f", "vm_number=5310") in new stack
    -- Executing [5310@short_number_calls:3] Dial("SIP/6010-0000010f", "SIP/5310,12,tT") in new stack
  == Using SIP RTP CoS mark 5
    -- Called SIP/5310
  == Extension Changed 5310[hints] new state Ringing for Notify User 6010
    -- SIP/5310-00000110 is ringing
  == Extension Changed 5310[hints] new state Ringing for Notify User 6010 (queued)
    -- Got SIP response 302 "Moved Temporarily" back from 10.9.43.101:5060
    -- Now forwarding SIP/6010-0000010f to 'Local/5173@voicemail' (thanks to SIP/5310-00000110)
[Jan 28 15:26:43] NOTICE[8399][C-0000008b]: app_dial.c:1005 do_forward: Not accepting call completion offers from call-forward recipient Local/5173@voicemail-00000006;1
[Jan 28 15:26:43] NOTICE[8399][C-0000008b]: core_local.c:734 local_call: No such extension/context 5173@voicemail while calling Local channel
[Jan 28 15:26:43] NOTICE[8399][C-0000008b]: app_dial.c:1111 do_forward: Forwarding failed to dial 'Local/5173@voicemail'
  == Extension Changed 5310[hints] new state Idle for Notify User 6010
  == Everyone is busy/congested at this time (1:0/0/1)
    -- Executing [5310@short_number_calls:4] Dial("SIP/6010-0000010f", "SIP/6310,30,tT") in new stack

According to

core_local.c:734 local_call: No such extension/context 6010@voicemail while calling Local channel

call is being forwarded to context voicemail with extension 6010 when it must be forwarded to short_number_calls context (same as step before in extensions.conf) with the same extension.

I don’t understand, why does it works like this?

Please, help.

Best Regards,
Nufay

So basically, my phone replies with

– Got SIP response 302 “Moved Temporarily” back from 10.9.43.101:5060

instead of forward call as it does if i forward a call after answering it.
Sounds like a problem with phone configuration, but all my lines are configured with

can_forward_calls=yes

what could cause my phone to reply with response 302 instead of forwarding?

Nothing. 302 is how phones request forwarding.