Symptom:
Steps:
1. Config three phones with share line: 8851A, 8841A , 8861A

8851A : two lines : 11118851  (max: 200, busy trigger: 200)   -- share line
                           11118841  (max : 200, busy trigger:1 )      -- share line

8841A: three lines:  11118841 (max : 200, busy trigger: 200)  -- share line
                            11118851 (max : 200, busy trigger : 1) -- share line
                            88519999 (max : 6, busy trigger: 2)  -- Non share line

8861A : two lines: 88611001 (max : 200, busy trigger : 200) -- Non share line
                           11118851 (max ； 200， busy trigger : 200)  -- share line

2. From phone 8851A first line (11118851) make 98 call session to Phone 8841A first line (11118841)  (97 hold call, 1 connected call)

3. From phone 8851A first line (11118851) make 50 call session to Phone 8861A first line (88611001), (49 hold call, 1 connected call)

4. End one call session on Phone 8841A
5. On Phone 8861A first line, hold the current connection call, Press "New Call" dial number 11118851

Phone 8851A can answer the call, but on Phone 8861A, the call session is blank.

Conditions:
Phones should configure Share lines and max call/busy trigger are set to 200.