unified highlighter methods works unexpected

[Szűcs Roland]

Hi All,

I use Solr 8.4.1 and implement suggester functionality. As part of the
suggestions I would like to show product info so I had to implement this
functionality with normal query parsers instead of suggester component. I
applied an edgengramm filter without stemming to fasten the analysis of the
query which is crucial for the suggester functionality.
I could use the Highlight component with edismax query parser without any
problem. This is a typical output if hl.method=original (this is the
default):
{ "responseHeader":{ "status":0, "QTime":4, "params":{ "mm":"3<74%", "q":"Arany
Já", "tie":"0.1", "defType":"edismax", "hl":"true", "echoParams":"all", "qf
":"author_ngram^5 title_ngram^10", "fl":"id,imageUrl,title,price",
"pf":"author_ngram^15
title_ngram^30", "hl.fl":"title", "hl.method":"original", "_":
"1585830768672"}}, "response":{"numFound":2,"start":0,"docs":[ { "id":"369",
"title":"Arany János összes költeményei", "price":185.0, "imageUrl":"
https://cdn.bknw.net/prd/covers_big/369.jpg"}, { "id":"26321", "title":"Arany
János összes költeményei", "price":1400.0, "imageUrl":"
https://cdn.bknw.net/prd/covers_big/26321.jpg"}] }, "highlighting":{ "369":{
"title":["\n <strong>\n Arany\n </strong>\n János összes költeményei"]}, "
26321":{ "title":["\n <strong>\n Arany\n </strong>\n János összes
költeményei"]}}}

If I change the method to unified, I get unexpected result:
{ "responseHeader":{ "status":0, "QTime":5, "params":{ "mm":"3<74%", "q":"Arany
Já", "tie":"0.1", "defType":"edismax", "hl":"true", "echoParams":"all", "qf
":"author_ngram^5 title_ngram^10", "fl":"id,imageUrl,title,price",
"pf":"author_ngram^15
title_ngram^30", "hl.fl":"title", "hl.method":"unified", "_":"1585830768672"
}}, "response":{"numFound":2,"start":0,"docs":[ { "id":"369", "title":"Arany
János összes költeményei", "price":185.0, "imageUrl":"
https://cdn.bknw.net/prd/covers_big/369.jpg"}, { "id":"26321", "title":"Arany
János összes költeményei", "price":1400.0, "imageUrl":"
https://cdn.bknw.net/prd/covers_big/26321.jpg"}] }, "highlighting":{ "369":{
"title":[]}, "26321":{ "title":[]}}}

Any idea why the newest method fails to deliver the same results?

Thanks,
Roland