I actually wish they would bring out a new firmware for the WAP571 that would take care of the stupid errors i am having around mDNS and deauthentication. I have now 3 WAP571's in play and all in all going really well but i was expecting more from Cisco, to be honest.
Have you reported the problem to Cisco small business forums? If they can reproduce it they will fix. This is assuming another vendor is not causing the issues. They will only test using Cisco products which makes sense since Cisco has nothing to do with other vendors products.
Can you not come up with a work around while you are waiting?
I pay no Cisco licensing fees. You can buy some but normally there is no licensing fee for Cisco small business networking devices. The key is using small business devices. You get free firmware updates for the life of the product.
I believe if want to use the Cisco umbrella system there is a licensing fee. Since I am at home I just use IBM's QUAD9, 9.9.9.9 for DNS and call it good. It is not as good but for home use it what I use. If you want to use Cisco's VPN I think you need to pay. You may get 1 Anyconnect free. I have heard it both ways.
I know I came from using Cisco PRO gear where every IOS costs money unless you pay smartnet maintenance which make it free for the maintenance fee once a year.
So buy all the Cisco WAP581-A-K9 wireless APs you want and upgrade them for free. They are a good wireless AP the best I have used.
Cisco's small business SG350 switches are layer 3 and a great buy.