Just replicating /etc/truststore does not solve this. You must copy the hmac/master keys files physically from the filesystem (/crx-quickstart/launchpad/felix/bundle25/data) too to the other instance. So the steps are:
1. Replicate /etc/truststore
2. Copy the hmac/master keys files physically from the filesystem ( e.g. /crx-quickstart/launchpad/felix/bundle25/data) to all other publish instances