Can I enter more than 20 1099-Rs? I have 24 1099-R forms, only 20 were imported, seems to be a limit.

Yeah..that's an issue, and an IRS limit.

Some brokers issue a 1099-R for every holding in your account, even if it's the same IRA or 401k account  (mine doesn't thankfully).

So...here's what you have to do........that might work

________________________________

You can (manually) combine 1099-R forms to chop the number down below 20 ....but ONLY IF: 

1) IF from the same broker & EIN....and for the same person

2)  IF the box 7 code is exactly the same on each of those combined

3) And a critical condition..... IF no tax withholding was done for the 1099-R forms being combined.

(added later)  #4)   the IRA/SEP/SIMPLE checkbox needs to be the same too

Otherwise, you will have to print out your tax return and file by mail.  (you can still combine the 1099-R's with withholding, but you will have to file by mail, and send the IRS copies of every tax form with withholding on it.

______________________

Next year.....see if you can remove $$ from only select funds, so that only a few re affected....of move some funds into the IRS's or 401k's cash holding inside that retirement account, and take only out of the cash holding every year.  Talk to your Broker/fund administrator to see how to arrange to do that.