QGIS 3.4 - Credentials to PostGIS connection constantly requested when panning the map

Question

I am using PostGIS databases linked to QGIS 3.4 with credentials set for all users, in other words user-authenticated workspaces. Note: The credentials are not stored within the project file or setup database connection within QGIS.

In QGIS 2.18, when loading a workspace the credentials were requested only once. Even if the workspace was used for a long time, when the map would be panned the credentials would not be constantly requested.

In QGIS 3.4 the same approach does not work. Once a workspace is loaded by entering first time the credentials, after a few minutes of zooming and panning, the credentials window pops up.

I have already tried the following, but with no success:

1. Setting up the PostGIS connection and saving the credentials as configuration on my machine.
2. Settings -> Options-> Network -> Cache Settings -> Authentication - Untick the setting to Automatically clear the connection authentication cache on SSL errors
3. Looked up in any possible setting related to database connections

The only workaround was to manually edit the local workspace and embed the credentials within it using a text editor e.g. finding the connection settings and replacing it with full configuration. I'd like to know if there is a possibility to sort out this issue without the need of manually editing the workspaces.