Here's the current engine I use for bing:
Code:
[Engine1]
Displayname=New Bing
QueryString=https://www.bing.com/search?q={KEYWORD}&sp=-1&pq{KEYWORD}&sc=1-49&qs=n&sk=&first={PAGENUM}&FORM=PORE
MustBeInLink=http
MustNotBeInLink=microsoft.com|overture.com|msn.com|bing.com|microsofttranslator.com|q=site:http
JustBeforeLink=href="
RightAfterLink="
PageStart=1
PageInc=10
NextPageMarker=">Next</a>|">Next</div></a>|class="sw_next">|title="Next page"
Translation=%3f=?|%3d==|%26=&|%3a=:|&=&|%2F=/
headerData=
Referer=0
SSLVersion=0
Favicon=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
GracePeriod=0
UserAgent=Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:88.0) Gecko/20100101 Firefox/88.0
Selected=1
DetailedSelected=0
FollowRelocation=1
AddRelative=
AddFieldValue=
ClearCookies=0
ListMode=0
ReadOnly=0
You can save that as bing.dat then import it via the harvester engine configuration. If that doesnt work then I'd look at proxies being an issue - I've seen bing start throwing out some ip bans where they just refuse to show any results, but still nowhere near as often as Google.