This concerns how the mobile app decides to display and play content which has already been downloaded to the device for offline play.
In areas with unstable cellular connections, the Spotify iOS app cannot decide if it should pull the content from online or directly refer to the downloaded content which is readily available on the device.
If the app decides that it should try to load an album view from the cloud, even if that exact album is downloaded for offline play, it will attempt for quite some time until it times out and even then does not revert to showing the offline downloaded content.
I've been advised to manually go and turn on Settings->Playback->Offline Play when I'm in areas of variable cellular connection, which isn't a great user experience.
If I do go and force Offline Play, the albums load immediately and without issues.
Please change the timeout for accessing online content and provide better error codes, more proactively change to offline play during excessive timeouts, and especially prioritize displaying and playing content from the device if it is already downloaded to the device itself - don't try to go online for content which is already here.