JIRA API 400 Bad Request

Good morning/afternoon/evening 🙂 

I've been connecting to the JIRA API for some time now and it's been working fine up until now, where I am getting a bad request error. I have not changed anything in the code that makes the request to Jira. I have connected with the API key and checked that the projects, fields and custom fields all still exist in Jira, which they do. Can anyone identify what could be causing the error?

I have replaced the company name to keep it anonomised. Any help will be greatly appreciated!! 

let
BaseUrl = "https://ANONCOMPANY.atlassian.net/rest/api/3/search?jql=project in ('BIM', 'BCM')&fields=key,statuscategorychangedate,customfield_10076,resolution,lastViewed,priority,assignee,status,creator,reporter,issuetype,project,resolutiondate,created,updated,customfield_10091,customfield_10095,customfield_10129,summary,customfield_10085,customfield_10086,customfield_10087,customfield_10070,customfield_10078,customfield_10090,description,customfield_10132,customfield_10088",

JiraIDPerPage = 100,

GetJson = (Url) =>
let
RawData = Web.Contents(Url),
Json = Json.Document(RawData)
in Json,

GetJiraIDCount = () =>
let Url = BaseUrl & "&maxResults=0",
Json = GetJson(Url),
Count = Json[#"total"]
in Count,

GetPage = (Index) =>
let Skip = "&startAt=" & Text.From(Index * JiraIDPerPage),
Top = "&maxResults=" & Text.From(JiraIDPerPage),
Url = BaseUrl & Skip & Top,
Json = GetJson(Url),
Value = Json[#"issues"]
in Value,

JiraIDCount = List.Max({ JiraIDPerPage, GetJiraIDCount() }),
PageCount = Number.RoundUp(JiraIDCount / JiraIDPerPage),
PageIndices = { 0 .. PageCount - 1 },
Pages = List.Transform(PageIndices, each GetPage(_)),
JiraID = List.Union(Pages),