My DS2 was born a week prior to lockdown starting. I was really sad that my mum couldn't spend time with him, but was at home with furloughed DH and DS1 (2 years old)
I cried every hour of the day that I was awake, I couldn't say why, but put it down to lockdown. I didn't feel overwhelming love for my son like I did straight after DS1 was born. I looked after him and loved him but it was more of a chore and didn't feel natural and I felt like I didn't know what to do, despite being the exact opposite with DS1. I was so so so careful and by the book with DS1, and less so with DS2 because I didn't care about him as much 
with DS1 I was so in control and in love and felt like a natural. My overwhelming feeling was sadness and guilt for not feeling as close to him as I ought to, and knowing that I loved DS1 more than him.
He's now 15 weeks and and absolute joy. I couldn't love him more if i tried.
I have spoken to DH about this recently, saying I wonder if I was suffering with PND and described how I was feeling. I didn't admit it at the time as I was embarrassed and ashamed to do so.
DH keeps making light of it now, saying things like 'as if you didn't love him as much' or 'do you feel like you love him today?' And laughing. I've just nipped off to the loo to write this post and have a little cry