Bitbucket Branch Source plugin v2.2.3 would instantly receive notifications from Bitbucket and begin building within 1-2 seconds.  However, after upgrading to 2.2.4, it could take up to 4 minutes to process the notification. 

When manually selecting build, the job would hang at "Started by user ..." for 3-4 minutes before actually doing the build and checking out the pipeline script.

2.2.3 Logging (after switching back):

[Wed Oct 25 22:37:30 EDT 2017] com.cloudbees.jenkins.plugins.bitbucket.hooks.PushHookProcessor$1 UPDATED event from 10.1.201.237 ⇒

https://<jenkins server>/bitbucket-scmsource-hook/notify

with timestamp Wed Oct 25 22:37:24 EDT 2017 processed in 1.7 sec

2.2.4 Logging:

[Wed Oct 25 22:25:40 EDT 2017] com.cloudbees.jenkins.plugins.bitbucket.hooks.PushHookProcessor$1 UPDATED event from 10.1.201.237 ⇒

https://<jenkins server>/bitbucket-scmsource-hook/notify

with timestamp Wed Oct 25 22:22:12 EDT 2017 processed in 1 min 9 sec

Notice the timestamp in 2.2.4 is over 3 minutes older than the logging timestamp.  Also, 2.2.4 shows it took 1 min 9 sec to process, whereas 2.2.3 only took 1.7 sec.  

Doing a thread dump of Jenkins appeared to show that it was doing an SCM fetch, but I don't know what on, since nothing I could find was being loaded.

It's also worth noting that this was working fine before upgrading to 2.2.4, then it worked fine again after reverting back to 2.2.3, so this is definitely an issue introduced in the latest version.

Please let me know if any other logging would be useful.