I can not start a short dca bot if there is an existing long trade on a coinpair.
Need to lookup that error in message-logs.
My workaround is to remove that coin from the multi selection and remember to re-add it again later.
Please ignore that trade until it is closed and allow the bot start, then re-add to list automatically in the background. This would be a way better user experience and is the standard behaviour on other trading platforms I used.