CLONE - [XDCR] Compression type not set after upgrade to 6.0.x

1) Flash 5.1.2-6030 on two 2 node clusters
2) Setup replication between the 2 clusters
3) Do a rolling online upgrade from 5.1.2-6030 to 6.0.1-2037 (https://docs.couchbase.com/server/6.0/install/upgrade-online.html)
4) Open "Edit replication" dialog box

It is observed that "Compression Type" dropdown is not pre-populated with value "Auto" and this error text is displayed "Unable to translate user input to internal compression Type". Same behavior is observed in the "Add replication" dialog box as well.

However, user can choose an option from dropdown and set compression type without any issues.

curl -X GET -u Administrator:password http://127.0.0.1:8091/settings/replications

{"checkpointInterval":600,"compressionType":0,"docBatchSizeKb":2048,"failureRestartInterval":10,"goGC":100,"goMaxProcs":4,"logLevel":"Info","networkUsageLimit":0,"optimisticReplicationThreshold":256,"sourceNozzlePerNode":2,"statsInterval":1000,"targetNozzlePerNode":2,"workerBatchSize":500}