The track events are using an encoded GET request which fails for larger payloads. I don't know the exact length but beyond a certain size Klaviyo rejects the events with 414 Request-URI Too Large. Klaviyo's API docs recommend sending the track event using the POST method.
https://github.com/klaviyo/magento2-klaviyo/blob/688b85ea27649ef0a4e56f0f4e6edcd5d020e09c/Helper/Data.php#L131
The track events are using an encoded
GET
request which fails for larger payloads. I don't know the exact length but beyond a certain size Klaviyo rejects the events with414 Request-URI Too Large
. Klaviyo's API docs recommend sending the track event using thePOST
method.https://apidocs.klaviyo.com/reference/track-identify#track-get