AWS AppFlow / Bug on saving the flow for GA4 with the filter by `startDate`

The situation is the following. I use the appflow to pull data from Google Analytics 4. There is a restriction for using filters in the flow, that is we cannot use the field startDate in the filter if we configured an incremental data refresh using that field. It's okay. The problem is that when we configured an incremental refresh previously and want to switch from Run flow on schedule to Run on demand the flow seemed not to release the field startDate from the incremental refresh option. So all attempts to add the field startDate to the filter to run the flow manually for the specific period fail on the step of saving the flow with the following error: Create Flow request failed: [Task Validation Error: Field used in incremental pull cannot be used as a filter parameter. Remove the filter with startDate field from the flow.]

The only way to overcome this issue is to completely recreate the flow from scratch without using the incremental refresh option. The problem has existed for quite long. Could you please fix it? Thanks.