I looked up your phone and you only have 3GB of RAM. Is this a new occurrence or something that used to work and now doesn't?
How often do you restart your phone? Restarting your phone is good for its health. It stops processes that aren't needed, restarts and refreshes processes that are. It also clears caches and is good for the overall system health.
Have you tried closing all apps that appear in your recent tab? Clearing this list by closing all apps can free up RAM. It can't make a system out perform its capabilities but it can get you as close to the device's maximum.
Are you using any "Saver" apps? Memory saver, Data saver, RAM booster? These apps usually cause just as much damage as they claim to prevent. Many times they run in the background taking up valuable resources like battery and RAM and devices often perform better without them.
Is the build you note, the original ROM? Are you rooted? Rooting can affect the performance of a device and with access to so much of the OS it very easy to foul something and create performance issues.
I don't know this device but on my Samsung I have a setting section called Divice Care where I can see things related to battery, memory and storage, Under my Memory tab I can see how much of my RAM (memory) is being used, how much each app I've used has used, and some other information. Have you looked at anything like that on your device? How much RAM is your device using at rest, so to speak? This would be a random check after normal use in the middle of the day or something.
If you were able to find the section I mentioned above, do you have a "clean", "clear" or "stop" option in this area, that temporarily shuts apps down until reopened or in demand?
Everything before this was troubleshooting and fact finding. My advice, if you have enough RAM for it to work, would be to start simple. Check to see if either of these apps in on you sleeping apps list. Apps that are put to sleep the by the OS stop running in the background and restart every time they are opened. To find your sleeping apps list look at your settings menu, use the search bar at the top to search "sleeping", and you should find Sleeping apps and Deep Sleeping apps, check these lists and remove any apps you find here that you want to be able to run in the background. Next would be regular restarts. To keep your device running smoothly restarts clear caches and restart processes that have become stale so to speak and is just a general good practice. The last thing you can try would be adding these apps to the "never sleeping apps" list. This list should keep apps that are opened, and haven't been closed, it should keep them active in your RAM.
Answer our questions and let us know what you find.