This happens to me too. Sometimes even my mn will be alone in the list of masternodes... but still receive payment. Others have mentioned this phenomena as well so we're not unique.

Best advice I could give you to start would be to fill out an excel sheet or something like it with the balance in each mn at the end of each day. After a few days, you can look at the changes in balances to make sure all of your mns are receiving rewards. Make sure your nodes are fully synced before issuing "masternode start" command... and usually everything is peachy even though the list function is a bit buggy.

If a node goes a few days with no payment I usually issue a "masternode stop" command, followed by a check to make sure the node is fully synced, followed again by the "masternode start" command. Usually this is enough but occassionally the node needs to be restarted.

When I receive the message "Masternode started succesfully"... I estimate the mn does in fact start successfully 99.9% of the time... you can be pretty confident once you receive this message, but it is wise to track it via excel or whatever as well.

As a sidenote, since I started running 8bitd on ubuntu server rather than desktop, I have had very very few errors compared to on desktop. Running 12 currently on one machine with more than enough ram, my processor seems to be the limiting factor.

These issues should be non-existent on the new chain/codebase, I think pivx for instance has a list on the web somewhere of an updated list of active mns, maybe we'll have something like that soon.