One explanation is that the VPS is not powerful enough to start up your EA.
How many charts opened in your terminal? During low volatility hours, did you have better chance to start it up?
Another reason is due to the mis-configure of custom indicator, that may cause memory leak
One solution is to buy a pc dedicating to your trades. It may be even cheaper than VPS in long term. If your custom indicator is complicated, the demand in pc speed is much higher than expected
Try to open just one chart. If it works, that means that is not your EA problem