Thunderbird calendar not respecting timezone when subscribing to RFC5545-compliant iCal/ICS?

I'm attempting to add the public stream schedule for a Twitch streamer to my calendar in Thunderbird, which is possible because Twitch does offer an API endpoint to get a streamer's schedule via RFC5545-compliant iCalendar file (https://dev.twitch.tv/docs/api/reference#get-channel-icalendar). However, Thunderbird doesn't seem to be respecting the timezone information in Twitch's iCal data and it is not converting event times to my local timezone (America/Chicago). If I open one of the imported events from the iCal in Thunderbird in Edit mode and enable the Show Timezones option, Thunderbird appears to be interpreting the imported start and end times as "Local Time" instead of the timezone specified in the iCal. If I change the timezone in Thunderbird's calendar settings, the start and end times of the calendar events imported from Twitch do not update either. This happens with ANY iCal from Twitch, but for the sake of illustration, the specific public calendars I'm attempting to add are: > https://api.twitch.tv/helix/schedule/icalendar?broadcaster_id=519794491 > https://api.twitch.tv/helix/schedule/icalendar?broadcaster_id=425292962 Other software (GNOME Calendar and the Open-Xchange-powered platform my e-mail provider uses) is correctly interpreting the timezone data in Twitch's iCal so the issue appears to be in Thunderbird. Any suggestions?