ST knows about this bug.
Feb 27, 8:28 AM MST
Thank you for contacting Samsung SmartThings Support.
Apologize for the inconvenience. Yes it is a known issue from our end, in the meantime there is a work around you can do, type the negative value in a browser or notepad and copy and paste the number
Even though it’s not always easy to hear. This has already been forwarded to our engineering team to take care of the issue. They’re currently working on this issue to sort it out.
Thank you for your feedback. We appreciate the time you have taken to share with us. your feedback is extremely valuable. This type of input from our customers is instrumental in shaping SmartThings and we appreciate hearing it
Thanks for everything. If there’s anything else at all we can do for you, please do not hesitate to reach out.