Add host to cluster in SDDC Manager is failing at - Not enough IP addresses available in the IP address pool HostTep

Products

• VMware SDDC Manager

Issue/Introduction

Add host to cluster in SDDC Manager is failing at - Not enough IP addresses available in the IP address pool HostTep.
Error in SDDC Manager UI:

Errors in /var/log/vmware/vcf/domainmanager/domainmanager.log

 yyyy-mm-ddThh:mm:ss INFO [vcf_dm,xxxxxxxxxxxxxxxxxxx,606a] [c.v.v.h.s.v.IpAAddressPoolSpecValidator,dm-exec-6]  15 IPddresses are available for NSX static IP Pool of ID HostTep
yyyy-mm-ddThh:mm:ss INFO [vcf_dm,xxxxxxxxxxxxxxxxxxx,606a] [c.v.v.c.f.p.nsxt.helpers.NsxUtils,dm-exec-6] There are 12 IP addresses blocked for NSX static IP Pool HostTep
yyyy-mm-ddThh:mm:ss ERROR [vcf_dm,xxxxxxxxxxxxxxxxxxx,606a] [c.v.v.h.s.v.IpAAddressPoolSpecValidator,dm-exec-6] There are no enough IP addresses in the IP address pool HostTep. Required 4, available 15, blocked 12

After the error has occurred, it is confirmed that there are enough IP addresses left available in the IP pool by checking NSX manager UI.

Environment

VMware Cloud Foundation 5.x

Cause

Ip addresses where not released from in memory map used in parallel add host workflow, this is known issue in VCF 5.x.

Resolution

Workaround: 
To reboot the SDDC Manager.