Can we run a collections report for a specific month in A/R?

Yes, @Isabelle4. We can generate a monthly report for our collections in QuickBooks Online. 

A Report on Collections displays all customer transactions like open invoices, credit memos, unapplied payments, unapplied deposits, and overdue.

You can select your preferred date: today, weekly, monthly reports based on the detail that you require.

Here's how:

1. Click on Reports from the left pane.
2. Look for Collections Report from the search box.
3. Select the Report Period that you want.
4. Click on Run report.

Please see screenshot below for your reference:

You can also run the Accounts receivable ageing detail report to see the actual cash collections for the week, month, or any other time period. This report sorts a company's unpaid invoices by the number of days outstanding. Then, customize it by selecting a specific date range to focus on the details you want to see.

Here's how:

1. On the left panel, select the Reports menu.
2. Select Accounts receivable aging detail from the search bar.
3. Select the Customize option. From the Report period drop-down menu, select the appropriate date or month.
4. Customize or filter the remaining options.
5. Lastly, hit Run report.

Click here for more information on how to customize your reports to format the design so that the data appears in the right place: Customize reports in QuickBooks Online.

Come back if you still need to run other reports or concerns about your QuickBooks account. I'm always willing to provide workaround. Keep safe.