Looks like they are having the same long haul symptoms as other that had moderate to heavy cases and recovered but never fully. So, basically, what it says is those who think they are strong and will get by easily, well almost 30% end up with life altering symptoms weeks later, breathing, heart problems, brain fog, etc.....
Get vaxxed is the message.
http://www.dailymail.co.uk/health/article-9344069/Nearly-Covid-long-haulers-NO-symptoms-diagnosis.html