Don't you think that is jumping the gun? What if it was installed by a dummy with long line length without compensation? What if one of the sensors went awry? It could be a number of things - even though a leak is very possible. And unless it's a very old model, all Daikin m. splits have inverters, and the inverter compressor very rarely has issues. I'm not responding to start a pissing contest... but I am quite familiar with this equip and there can be a slough of other little quirks. For instance, what if the unit is drawing cooler air through an unsealed wall penetration across the indoor ambient sensor, causing a misread and to satisfy target temp prematurely? I will get out of your thread after this post, no offense or disrespect intended whatsoever my fellow hvac guy....
To the OP, there's no question as to what your next step is, the professional that installed your equip needs to come back out and assess the problem. Whatever it may be, leak or not, your expensive equipment could endure further damage without doing so.
You can look around at the field flare connections at both units (where the copper refrigeration pipes connect) and see if there's any sign of oil on or near the joints - this is a telltale sign if a leak caused by poor installation practices. But get your HVAC out asap.
Good luck sir,
Myco