missing some event traces

**Describe the bug**
Events table returns lower number of ROIs compared to dff valid ROIs and cell_specimen_table.valid.sum()

**To Reproduce**

> session_name = 'multiplane-ophys_721291_2024-05-16_08-57-00'
> bod = BehaviorOphysDataset(...)
>
> cstable = bod.cell_specimen_table
> print(set(cstable[cstable.valid_roi].index.values) - set(bod.events.index.values))
> print(list(set(bod.events.index.values) - set(cstable[cstable.valid_roi].index.values)))
> print(bod.events.shape)
> print(bod.dff_traces[~bod.dff_traces.noise.isna()].shape)

**Expected behavior**
events table having the same shape of no_nan dff_traces table and number of valid ROIs