There is network scheme on the attached picture. Summarization of routes from area 0 (10.0.1.0, 10.0.2.0, 10.0.3.0, 10.0.4.0) into 10.0.0.0/8 is configured on router B (review the attached config). They appear as individual prefixes in "Summary Net Link States (Area 5)" on router B, but not as whole 10.0.0.0/8 (review the show ip ospf database). There is virtual-link between routers B and I. If I remove this virtual-link, all work properly and I see only one summary prefix in area 5. But with virtual-link I see 4 individual prefixes in area 5. How this virtual-link can influence the summarization?
Just as a follow-up, The scenario I described above is not valid as router I would not generate a type 3 LSA for 10.0.1.0/24 in area 5 as it is the transit area.
Also, if you want the "area range" on router B to take effect despite of the virtual-link (i.e. disable the behavior stated in RFC2328), you can use the command "no capability transit", as described in the following document: