mongoengine contains and exists in the same query

Is it possible to have a contains and exists call in the same query in mongodb, specifically mongoengine for python?

The data I need to parse is stored in a mapfield where I need to go into the keys and identify if the key of interest exists and contains a specific word. here is an example of the data structure

{_id: "Final Fantasy"
"playtime": {"2024-01-01 1:00:00" : {"deaths":5, "levels_gained":10},
             "2024-01-03 4:00:00" : {"deaths":2, "levels_gained":5},
             "2024-01-07 3:00:00" : {"deaths":2, "levels_gained":5}}}

Currently to find very specific keys in the mapfield, I perform the following

entries: List[GameDoc] = []
dt_str = "2024-01-03 4:00:00"
query = Q(**{f'playtime__{dt_str}__exists': True})
entries.extend(GameDoc.objects(query))

but when I try to include "contains" in the query, it doesn't find the documents. as an example, I want to find all documents that contain the date "2024-01" regardless of the other items in the key.

query = Q(**{f'playtime__{"2024-01"}__exists': True})
query = Q(**{f'playtime__{"2024-01"}__contains': True})