Could be overwatered and the roots are rotting? It should not be flopping unless it was dried out but then upon watering it should be upright again in an hour or two.

Outdoors last summer

Indoors after Xmas - the key is to barely water in winter.

Blooms in early Feb this year are insignificant

Make sure it gets plenty of light - I had it in deep shade for most of the summer this year and it shows. Since moving it to more light, it has improved a lot.

Here it is mid-August with insect and falling debris damage but I will remove those leaves for possible propagation later on.

Thank you! I wasnt sure how mich light it could handle- thought all begonias liked shade, more or less. It's also due for a repot so I will check the root system out when I do. I know spring is ideal for repot but l.y. we got such an awful stink bug population in our house over winter that I'd rather wait to repot until right before bringing plants in for winter In about 4 wks. Hopefully, it'll cut down on bugs.

Just spray for the bugs and fungus/mildew if the soil appears okay. Begonias tolerate more light/sun than most of us realize. They can take a bit of shade too - six of one/half a dozen of another?

Last year it got sun from morning until around 2 PM when the sun moved to the other side of our deck. If I saw it in wilt then I knew it was time to water it. So I would say it loved the sun? This shot was 7/8/2017 and you can see maybe 1/4 of it is under the stairs.