I've finally decided to give a renew-setup a try... I've setup a new mn address/genkey and node seems to run smooth so far (recently stopped working after 1 day). Looks like user's with "old" masternode-address/genkey need to get on a new chain since there seems to be something changed recently?! Masternode.online reports my node now being up for about 1 day so far already going to earn again ...

May be this will help users having the same issues as me recently.