By default if a reoccurring meeting is submitted to a resource room the entire request will be denied. You can set thresholds to allow partial acceptance.
Here is a script that connects to Azure from powershell and sets the thresholds to 50% and/or 10 conflicts.
What will happen is if a user sends a request that would book 10 meetings and 3 of them conflicted it would book the other seven and decline the three. If there were five conflicts it would decline all of them.
$UserCredential = Get-Credential
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
Import-PSSession $Session
set-executionPolicy RemoteSigned
Get-MailBox -ResultSize unlimited | Where {$_.ResourceType -eq "Room"} | Set-CalendarProcessing -ConflictPercentageAllowed 50 -MaximumConflictInstances 10