Bounce rate up 50% after upgrading to PS 1.6

[outlet.ee]

I upgraded from 1.52 to 1.6 three weeks ago and GA says the bounce rate is up 50% since then (33% to 49%). After som digging, it turned out the increase comes from mobiles mostly - from 26% to 65%. Tablets remained the same and desktop slightly increased. I tested and it really is slow on mobile (both iOS and Android), using 3G, 4G and WiFi. At the same time the visitors has increased about 50%, the increase coming mostly from mobiles too. So i got more visitors, bit on the other hand i throw them away again, so there is no benefit in upgrading to 1.6 & responsive (had dynamic mobile version before that).

 

Any ideas why is is slow mobiles, or why the bounce rate has gone up so drastically?

[Dh42]

Does your site take longer to load now? You might look in your GA page speed section. That can increase your mobile bounce rate. 

[outlet.ee]

Yes, indeed it takes longer to load but only on mobiles. The page speed section gives the load times for the first 40 pages out of 6000+ pages only. But in reality it is slow, only on mobiles. Where shall I start looking?

[Dh42]

I would start trying to optimize the site for mobile display. That would help with things. 

[outlet.ee]

That's what I mean. I have no good idea where to start optimizing for mobile. If you were in my shoes, what would be the first 3 or so things you would look or do?