Proof of Stake coins have a dormant period ,
(varies per coin design)it may be that there are not enough non-dormant coins available to stake and maintain the blockspeed.
Noblecoin is one example of this , as it has days in between a few stakes.
https://chainz.cryptoid.info/nobl/This is because the few that still have stake-able coins don't have their coins spread out into enough blocks to maintain the blockspeed.
Noblecoin difficulty is extremely low at 0.00071932 .
Meaning if a big holder came along and did not sync first, he could rewrite days of the blockchain by accident or on purpose.
or
Network has forked so badly , it can't choose the correct chain, and just refuses all new blocks.
(Requires paying a developer to add a checkpoint to fix.) If you want to support a Proof of Stake coin,
1: You need enough coins staking to maintain the blockspeed and a decent difficulty to prevent history overwrites.
If you are unable to purchase any additional coins at an exchange , this is a hard task to accomplish
2. Running Block Explorer is required as no one can trust a coin without a 3rd party explorer running.
3. Paying an exchange listing fee,
4. Maintaining Nodes to sync new users
If you are not willing to do all 4 , then don't waste your time doing 1 , as all 4 are required.
FYI:
You are better off picking a Proof of Stake coin that
Is maintaining it's blockspeed.
Has a Block Explorer
Has an Exchange , (
any exchange is working is all you really need.)Has users already Maintaining nodes and providing a blockchain snapshot to speed up syncing
FYI2:
You can work at keeping a dead coin network running, but it will be expensive, and likely without reward.
Makes more sense to find a Live Coin Network and throw your support behind it.
Their are still many to choose from. However the weak ones will be dying over the next year or two in droves.
In PoS you need a dormant coin to run the blockchain, your node will not do this job that is why the block will not move up or stuck.
Fork can be a reason for it too, try to stake your coin and observe it. Will the block move up or not