Missing notifications

**Describe the bug**
Element misses some notifications, for now no clear sign of the possible cause/trigger.
Some one-on-one rooms trigger notifications, while some others don't.
I have the feeling, though no confirmation that this is consistent, that m.direct rooms with multiple participants (e.g. me, another user and a bot) don't trigger notifications.
Mentions in group chats sometimes don't trigger notifications, but this is certainly not consistent. (i.e. I missed some mentions a few days ago but received notifications for mentions today in the same room.)
Synapse logs do have entries like this after processing the message event: `synapse.http.client - 377 - INFO - http_pusher.on_new_receipts-290 - Received response to POST https://matrix.org/_matrix/push/v1/notify: 200`

**To Reproduce**
Steps to reproduce the behavior:
1. Ensure notifications are enabled for all messages in one-on-one chats and mentions in group chats (both plain and encrypted)
2. Receive a message in one-on-one chats or mentions in group chats
3. Wait for notification

**Expected behavior**
Receiving notifications is consistent

**Screenshots**
N/A

**Smartphone (please complete the following information):**
- Device: Oneplus 8T
- OS: Android 11

**Additional context**
- 1.0.10 - Google Play Store