Right now, the HubSpot Behavioral Events data transport mechanism uses the rather archaic method of sending data as a “pixel” request with attached query parameters that define the event data.
The issue is that these types of pixel requests fall on their face when implementing click tracking on navigation buttons/links that cause the page to unload before the request can be finished - this results in data loss on sites that aren’t build like Single-Page Applications (SPA).
The soluton would be to upgrade the requests to use the navigator.sendBeacon() API or fetch() with its keepalive flag enabled. Both of these methods are more durable than using fragile image requests to send analytics payloads.