Increased dosage help my anxiety?

I've been on 30mg since April/May and everything was fine, no side effects besides the typically crash mid-day. But, for some odd reason the last few weeks I was experiencing some anxiety. Feeling like my heart is pounding hard and my BPM would be 100-120 (I know checking my apple watch could increase this anxiety more) within 20 mins after taking my dose. I would just feel like that probably for an hour at work, and I eat a small breakfast then everything is fine after that. However, my pharmacy didn't have 30mg in stock, only 40mg and higher, so my psychiatrist prescribed me 40mg and told me try the water titration method. I decided just trying out the 40mg one day and days later I'm not experiencing the racing/pounding heart beat feeling after taking my dose it's been smooth ride. Has anyone ever experienced this?