Air carrier Captain reported a L bleed duct warning while in icing conditions and spoiler control problems during the descent.

Narrative

Flight ABCD ZZZ1 to ZZZ. Flight was operated normally with a slightly late departure from ZZZ1. Flight was in cruise flight on the ZZZZZX arrival into ZZZ around ZZZ [VOR] at FL190 and we encountered icing conditions; we then turned on the wing and cowl anti ice. During this time; we were in and out of icing conditions. We then received a master warning message for L Bleed Duct; so I reached up and turned off the wings and cowl anti ice because we had no ice indication; and we began to run the immediate action checklist for L Bleed Duct followed by the QRH. We then got a descend via the ZZZZZX with ATC; so we descended immediately to get away from known icing conditions and also because of the potential of depressurization issue associated with a BLEED DUCT. After completing the QRH checklist we told the flight attendant to prepare the cabin early. Then we started the next decent portion of the arrival and used flight spoilers. At this time the plane yawed/banked to the left and we then received IB Flight Spoilers and IB Spoilerons caution msg. Again; radios were transferred to the FO (First Officer) and I ran the QRH for both caution messages. The QRH deemed our reference speed to be higher and set and other tasks were completed. We then received clearance to descend from 8000- 5000 had a similar roll and yaw moment. Then we looked at FLT Control synoptic page the left inboard spoiler was yellow; and the right inboard spoiler was white. With that information I instructed the Flight Attendant to go look at the wings and see if they could see if the spoilers were in an upright position or not flat on the wing. They notified me that they thought they were partially out so at that time the FO and I consulted to request priority handling and we disused turning the Autopilot off to feel if we would have another moment. When we got switched to final approach frequency; we requested priority handling and notified ATC of a precautionary landing in ZZZ. I then advised the FA (Flight Attendant) of the precautionary landing and then made a passenger announcement to let them know the situation. We touched down in ZZZ on a normal landing at a higher speed; then normal because of the higher reference speed and got off the runway and went to the gate and everything else was normal.