If you are doing a reset, that seems to be normal. Since your metabolism needs time to heal and return to normal. 2 kgs is not a ton (about 4 1/2 lbs) so that could also be some water retention too depending on numerous factors (sodium intake, heavy workouts, time of month, etc). I gain about 3-4 lbs after hard workouts and during time of month. It depends on your physiology. I would check out the faq's on this board to really find out more.

If this is valid weigh-in time, morning after rest day when not sore and having eaten normal sodium meals, then weight gain should taper off to nothing.

Initial gain is because you are indeed eating above your suppressed TDEE, and until the metabolism increases, extra is extra and is stored as fat.
If you started lifting routine at the same time, you are additionally making improvements to body that means more retained water all the time, besides water in the muscle when sore.

Depending on how long you ate at suppressed levels and how fast your metabolism responds, 3 wks seems about avg time to level off.
So you have measurements now to compare in 3 wks. If still increases, probably eating above real TDEE, if measurements go down, eating below and still losing fat, so you don't know what your real TDEE is.