Unified highlighter not working properly with sentence boundary scanner

[SaiKiran_Vukyam]

ElasticSearch version used: 5.4.1
When using these(unified, postings) highlighter the fragments in the query response have some difference.

For example:
With this query: "fragment_size": 200,"number_of_fragments": 2
Unified highlighter gives: "Microsoft Azure (formerly Windows Azure) is a cloud computing service created by Microsoft for building, testing, deploying, and managing applications and services through a global network of Microsoft-managed",
"It provides software as a service (SAAS), platform as a service and infrastructure as a service and supports many different programming languages, tools and frameworks, including both Microsoft-specific"

With this query: "fragment_size": 150,"number_of_fragments": 3
Unified highlighter gives: "Microsoft Azure (formerly Windows Azure) is a cloud computing service created by Microsoft for building, testing, deploying, and managing applications",
"and services through a global network of Microsoft-managed data centers.",
"(SAAS), platform as a service and infrastructure as a service and supports many different programming languages, tools and frameworks, including both Microsoft-specific"

But for both queries Postings highlighter gives below snippets:
"Microsoft Azure (formerly Windows Azure) is a cloud computing service created by Microsoft for building, testing, deploying, and managing applications and services through a global network of Microsoft-managed data centers.",
"It provides software as a service (SAAS), platform as a service and infrastructure as a service and supports many different programming languages, tools and frameworks, including both Microsoft-specific and third-party software and systems"

Actual content of the field:
"Microsoft Azure (formerly Windows Azure) is a cloud computing service created by Microsoft for building, testing, deploying, and managing applications and services through a global network of Microsoft-managed data centers. It provides software as a service (SAAS), platform as a service and infrastructure as a service and supports many different programming languages, tools and frameworks, including both Microsoft-specific and third-party software and systems"

Request you to let me know why this behavior is not consistent in the returned snippets.
As the field is indexed with offsets, unified highlighter should behave same as postings highlighter right ?...... and also different queries returned same result(snippets) in postings highlighter which is not the case with unified highlighter. Please help me understand this. Unified highlighter is not giving snippets with complete sentences even with boundary_scanner:sentence

[jimczi (Jimferenczi)]

The unified highlighter uses the sentence boundary with a maximum size of 150 characters by default. This means that it can split long sentences in multiple snippets. You can control the maximum size with fragmentSize, if you set it with a very big value you should have the same behavior than the postings highlighter.