There is no Easy Installer for lake and no OTA Android Version Upgrade [1]. The reason for “missing builds” is a server outage; please update yourself from the Development Updates here is a recent fragment.
… however in cases like yours, as you observed, current builds are fully available, “historical” builds are missing.
How far back in Android version are your phones? [HOWTO] Give complete /e/OS version info easily for support, answers, comparison etc.
If still on Android 10 (Q) prepare yourself for a fresh install Install /e/OS on a Motorola Moto G7 Plus - “lake” including format data. If you still have Android 11 (R), less certain, Format data perhaps not a requirement but good practice. “Jumping” multiple Android versions carries increased uncertainty whether dirty upgrade will be “all fine”. Note, the linked “dirty upgrade” method was based on new build packaging starting from Android 13 (T) where now vendor firmware parts (blobs) are included for many devices / builds.
lake has available currently Android 13(T) and Android 14 (U).
- [1] Definitely not OTA for dev=community builds. OTA Android Version Upgrade only available for official=stable builds.