Valid users being blocked from submitting contact and donation forms

Valid users are being blocked when attempting to submit job application materials through a Contact Form 7 (version 5.0.1) form. I see in my CleanTalk log that several applicants have had to try four or five times before the form submission is approved. Message in log is *** Forbidden. Browser seems to be spambot. *** or *** Forbidden. You submitted too quickly. You may try again in a few seconds. ***

In addition, donations through two Give Donation plugin (version 2.0.5) forms are being periodically blocked (with the same error messages as above) when we are making them from our organization’s IP address. I’m also receiving a “DDoS protection is activated for your IP 71.185.29.34” message when I click on links in your weekly emails. I don’t know if these problems are related.

I do not believe we had this problem before we updated from 5.88 to 5.89 last week. I’ve been using the paid version of your plugin for several years now and it is absolutely one of the best plugins I’ve ever used. This is the first time I’ve had any problem at all so I hope we can resolve this quickly!

The page I need help with: [log in to see the link]