Open the file teslausb-headless-setup.log and post the contents here.
Since the file TESLAUSB_SETUP_STARTED exists, setup thinks that it got far enough to build the filesystem with the /boot folder where it moves the config file to.
Thanks, here it is;
Wed 22 Jan 23:46:18 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Wed 22 Jan 23:50:21 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Wed 22 Jan 23:51:31 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Wed 22 Jan 23:51:31 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Thu 23 Jan 00:17:32 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Thu 23 Jan 00:17:31 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Thu 23 Jan 00:18:31 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Thu 23 Jan 00:18:31 GMT 2020 : Setup appears not to have completed, but you didn't provide a teslausb_setup_variables.conf.
Thu 23 Jan 00:18:31 GMT 2020 : Grabbing main setup file.
Thu 23 Jan 00:18:41 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:18:55 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:17:31 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Thu 23 Jan 00:18:26 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Thu 23 Jan 00:18:26 GMT 2020 : Setup appears not to have completed, but you didn't provide a teslausb_setup_variables.conf.
Thu 23 Jan 00:18:26 GMT 2020 : Grabbing main setup file.
Thu 23 Jan 00:18:37 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:18:50 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:19:03 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:19:17 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:19:30 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:19:43 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:19:57 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:20:10 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:20:23 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:20:36 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:20:50 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:21:03 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:21:16 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:21:29 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:21:43 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:21:56 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:22:09 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:22:23 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:17:31 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Thu 23 Jan 00:17:32 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Thu 23 Jan 00:18:18 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Thu 23 Jan 00:18:18 GMT 2020 : Setup appears not to have completed, but you didn't provide a teslausb_setup_variables.conf.
Thu 23 Jan 00:18:18 GMT 2020 : Grabbing main setup file.
Thu 23 Jan 00:18:28 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:19:09 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Thu 23 Jan 00:19:09 GMT 2020 : Setup appears not to have completed, but you didn't provide a teslausb_setup_variables.conf.
Thu 23 Jan 00:19:09 GMT 2020 : Grabbing main setup file.
Thu 23 Jan 00:19:20 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:19:33 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:19:46 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:19:59 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:20:13 GMT 2020 : get_script failed, retrying
Thu 23 Jan 00:17:32 GMT 2020 : Detecting whether to update wpa_supplicant.conf
Sun 17 May 18:59:59 BST 2020 : Detecting whether to update wpa_supplicant.conf
Sun 17 May 18:59:59 BST 2020 : Setup appears not to have completed, but you didn't provide a teslausb_setup_variables.conf.
Sun 17 May 18:59:59 BST 2020 : Grabbing main setup file.
Sun 17 May 19:00:00 BST 2020 : Starting setup.
Sun 17 May 19:00:57 BST 2020 : Detecting whether to update wpa_supplicant.conf
Sun 17 May 19:00:58 BST 2020 : Setup appears not to have completed, but you didn't provide a teslausb_setup_variables.conf.
Sun 17 May 19:00:58 BST 2020 : Starting setup.
Sun 17 May 19:01:48 BST 2020 : Detecting whether to update wpa_supplicant.conf
Sun 17 May 19:05:57 BST 2020 : Detecting whether to update wpa_supplicant.conf
Sun 17 May 19:05:57 BST 2020 : Setup appears not to have completed, but you didn't provide a teslausb_setup_variables.conf.
Sun 17 May 19:05:57 BST 2020 : Starting setup.
Sun 17 May 19:06:20 BST 2020 : Detecting whether to update wpa_supplicant.conf
Sun 17 May 19:06:20 BST 2020 : Setup appears not to have completed, but you didn't provide a teslausb_setup_variables.conf.
Sun 17 May 19:06:20 BST 2020 : Starting setup.
Sun 17 May 19:08:43 BST 2020 : Detecting whether to update wpa_supplicant.conf
Sun 17 May 19:08:43 BST 2020 : Setup appears not to have completed, but you didn't provide a teslausb_setup_variables.conf.
Sun 17 May 19:08:43 BST 2020 : Starting setup.
Sun 17 May 19:09:29 BST 2020 : Detecting whether to update wpa_supplicant.conf
Sun 17 May 22:02:31 BST 2020 : Detecting whether to update wpa_supplicant.conf