Based on the facts that API keeps responding with HTTP 300 (multiple choices) and the self urls are weird (e.g., "http://192.168.21.236:15868/v1/instance-ha/v1"), I'd say the endpoints were improperly registered and should perhaps not include a certain path /instance-ha.
Based on the facts that API keeps responding with HTTP 300 (multiple choices) and the self urls are weird (e.g., "http:// 192.168. 21.236: 15868/v1/ instance- ha/v1"), I'd say the endpoints were improperly registered and should perhaps not include a certain path /instance-ha.