Cannot pause/unpause a campaign via the API

We have two campaigns that fail to update the is_active status. The update for all the other ones work fine.

We use the https://developers.taboola.com/backstage-api/reference/update-a-campaign endpoint and send the following payload:

{
"is_active": false
}

As a result, we get this:

{
"http_status": 400,
"message": "Number of exclude countries exceeded the allowed amount",
"offending_field": "geo_targeting",
"message_code": "campaign.geoTargeting.server.error.GENERIC"
}

How can we update these campaigns? Any idea? It looks like a bug.