Data Syncing loading and loading

I am trying to connect Mongo Dabatase with Metabase where the database has 2.5 million documents / records. But after connecting its almost 2 hours gone metabse still showing loading / syncing.

For your info I have added another mongo database from same server which have almost 1 millions data and it syncs withing 3 minutes.

My post diagnostic info as below:
"browser-info": {
"language": "en-US",
"platform": "Linux x86_64",
"userAgent": "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36",
"vendor": "Google Inc."
"system-info": {
"file.encoding": "UTF-8",
"": "OpenJDK Runtime Environment",
"java.runtime.version": "11.0.15+10-Ubuntu-0ubuntu0.20.04.1",
"java.vendor": "Private Build",
"java.vendor.url": "Unknown",
"java.version": "11.0.15",
"": "OpenJDK 64-Bit Server VM",
"java.vm.version": "11.0.15+10-Ubuntu-0ubuntu0.20.04.1",
"": "Linux",
"os.version": "5.4.0-110-generic",
"user.language": "en",
"user.timezone": "Etc/UTC"
"metabase-info": {
"databases": [
"hosting-env": "unknown",
"application-database": "h2",
"application-database-details": {
"database": {
"name": "H2",
"version": "1.4.197 (2018-03-18)"
"jdbc-driver": {
"name": "H2 JDBC Driver",
"version": "1.4.197 (2018-03-18)"
"run-mode": "prod",
"version": {
"date": "2022-05-02",
"tag": "v0.43.0",
"branch": "release-x.43.x",
"hash": "ee686fc"
"settings": {
"report-timezone": null

Hi @mostafaemon

Latest release is 0.43.1:

You should migrate away from H2 if you are using Metabase in production:

Check the logs, when you sync to see if there's any errors:

If most "tables" are synced fine and you just want to remove the sync spinner, then follow this: