Watchdog expired is not a problem, your MN is still running and will recieve rewards as normal.

As for lack of rewards, we occasionally experience chain stalls if someone with a large amount of hashpower disconnects. It's most likely to be the cause of any periods with no rewards. This stalling is always a temporary situation and service resumes as normal as soon as the remaining miners find the next block. We have plans in place and a wallet dev working on converting our chain to Equihash_192 in the hope that it will smooth out the problem because it's not supported by big-rig rental places like nicehash. The problem should also vanish when Touriva has matured further as a project and has a larger number of miners operating. With a bigger mining pool the disconnection of a single large miner will have less of an effect.