As you mentioned the browser information shown by the Dashboard is indeed parsed from the raw user agent information available from the logs. Given you modified the user agent string the parsing is failing to identify the browser, however, you should be able to still obtain the raw user agent information directly from logs and in this way obtain the desired information.
You can use the
/api/v2/logs endpoint and explicitly specify the
user_agentfield as one of the fields to be included for retrieval as part of the
fields parameter (also implies that