Online percentage going down

Since some days the online percentage is going down. No changes in the pc or network and in two different nodes in different places. One of them has now 90% the other 98%. The errors are :

ERROR contact:service ping satellite failed {“Satellite ID”: “1wFTAgs9DP5RSnCqKV1eLf6N9wtk4EAtmN5DpSxcs8EjT69tGE”…

and

ERROR piecestore upload failed {“Piece ID”: “BX6GHP2BQU27Z6NSP5I42NTFSYJ7PRNQI65MXI7VQQAKDKFHT7DQ”, “Satellite ID”: “12EayRS2V1kEsWESU9QMRseFhdxYxKicsiFmxrsLZHeLUtdps3S”, “Action”: “PUT”, “error”: “unexpected EOF”, “errorVerbose”: …

What happend? How can I resolve it?

Your node was not available for satellites.
I would like to suggest to setup a port monitoring: How do I check my node when I'm away from my machine? - Node Operator

If you want to know, when your node was not available, you can use these scripts:

Regarding how to fix - check your router (for example - reboot it at first), if offline events disappear or reduce - then you know what to blame.
If it’s not - then it perhaps your ISP. You can be sure only after setup of port monitoring.

Regarding satellites you can see the status there:
https://status.storj.io/