Overflow and timeline not working for Schedule Block with multiple parents

Steps to reproduce:
1. Create new LP
2. Add 3 Schedule Blocks (named: S1, S2, S3), each can contain max 1 item (hero view)
3. Set overflows: S1 -> S3, S2 -> S3
4. Add one content item to S1 ("Now" timestamp). Example: Valencia, Spain
5. Move timeline forward, add one content item to S2 (timestamp: t1). Example: Ethiopian Cuisine.
6. Move timeline forward, add one content item to S1 (timestamp: t2) Example: Kochin, India
7. Publish LP

Expected:
In view mode, "Now" timestamp should show:
S1: Valencia, Spain
S2: -
S3: -

Actual:
S1: Valencia, Spain
S2: Ethiopian Cusine
S3: -

Moving the timeline forward (after t2) should show:
S1: Kochin, India
S2: Ethiopian Cuisine
S3: Valencia, Spain

Actual:
S1: Kochin, India
S2: Ethiopian Cuisine
S3: -

No errors in console/logs are visible.