There 3 common reasons for refresh issues :
1 – your phone is in ‘low memory’ state. The limit is between 50 and 300Mb of free internal memory (not storage), it depends how the manufacturer configured Android kernel sweeping aggressivity. In that state, Android kernel kills all services to free memory. If he kills my service, no more refresh is possible … so, you can check if your phone is no in ‘low memory’ with a tool such as ‘log collector’ tool (free on the market). So, be sure to keep at least 30Mb of free internal memory.
Nota: be careful, “internal memory” is not “storage memory”.
2 – you use a software like “task Killer” to free memory or kill apps. Same reason: kill service = no refresh. (Nota : killing an application can have side effects on other applications !!!)
You can use a tool such as ‘Task killer’ to check free memory and free memory if required… but avoid killing services.
To test if it is a bug or not, you can try to reboot your phone and see if it refresh correctly.
3- you use a battery saver app (like Greenify) or battery saving mode integrated by the manufacturer. Still the same reason …