Downloaded articles are not available when losing connectivity

[GLLM]

Hi @Alkarex !

First : I really love FreshRSS, as well as your forked EasyRSS app. Millions of thanks for it !!!!

I am hosting FreshRSS 1.7.0 (with mysql) on a Ubuntu 16.04 server / Apache2.

I am using Android 7.0 on a Samsung Galaxy 7 Edge phone.
On this device, I installed your EasyRSS.
I sync automatically every x hours, both on WiFi and 4G.
Pictures preloading is activated. States are immediately synced.
I use HTTPS.
I store the possible max number of articles : 4000

I have a problem when I'm offiline, i.e. I enter Paris infamous metro, so I loose any connectivity I could have hoped for.
Prior to entering the offline-zone, I always download (trigger manually a sync) my articles : header + content. Please note that I also set the app to download any pictures of the articles.

If I go in the metro, I will not be able to open any of my articles (unread, favorites, all).
I usually browse my articles using the unread section.
If I open any folder (containing a subset of RSS feeds), I wont see anything. It's empty, and until I get some network back : I wont be able to read my articles.

I found a workraround, but it's not handy :
after I synced my articles (with photos), I need to open once any folder I want to browse when offline.
Any folder not opened before going offline (loosing 4G connectivity) will not be available. And if I enter one, it will make me unable to open the sections/folder I did open on purpose

For instance, If I have folder for news, computer, photo and travel folders, if I want to read articles from news and photos, priori to loosing connection, I need to enter these 2 folders until I see articles in it.
If I do so, will be able to see articles from them.
Now, if I go to an un-opened section such as travels : I wont be able to see any articles, in addition to making the news + photos unavailable.

Do you see what could be causing this.

[Alkarex]

@GLLM Thanks for the kind words :-) EasyRSS is in need of a bit of maintenance for the cashing indeed.
I lack time for EasyRSS (when I have some free time for open source, I use it mainly on FreshRSS) so feel free to spread the word that help is welcome here.