When refresh dataset, getting error - There was an error when processing the data in the dataset

I have created a .pbix file with 8 reports using Power BI Desktop and published to app.powerbi.com. When I tried to refresh the dataset, I am getting below error.

Data source error{"error":{"code":"ModelRefresh_ShortMessage_ProcessingError","pbi.error":{"code":"ModelRefresh_ShortMessage_ProcessingError","parameters":{},"details":[{"code":"Message","detail":{"type":1,"value":"The operation has timed out"}}],"exceptionCulprit":1}}} Table: report_data_source. Cluster URIWABI-AUSTRALIA-EAST-A-PRIMARY-redirect.analysis.windows.net

The value (error occurred table name) of the Table (Table: report_data_source) is getting changed time to time. There are more than 50 tables used in this report and show the name of one of them as a Table.

I have checked the API and it's getting the request from Power BI and send the response within 30 secs without issues.

For the reference, query of report_data_source as below.

let
    Source = Json.Document(Web.Contents("https://bishan.me/api/getPBRData"))
in
    Source

And other tables are using report_data_source as below,

let
    Source = report_data_source,
    annual_report = Source[annual_report],
    #"Converted to Table" = Record.ToTable(annual_report),
    #"Removed Bottom Rows" = Table.RemoveLastN(#"Converted to Table",1),
    #"Changed Type" = Table.TransformColumnTypes(#"Removed Bottom Rows",{{"Name", type text}, {"Value", type text}})
in
    #"Changed Type"

When I am refreshing dataset from Power BI Desktop, It's working without any issue. I am getting the dataset refresh issue only in app.powerbi.com with Refresh Now and Scheduled Refresh options.

What could be the issue?