the ultimate workaround is to input manually... 1099-INT and DIV are usually straightforward to input and you have to take care of adjustments/supplemental tax info either way if those apply to you (e.g. US Gov obligations, Foreign taxes, accrued interest etc). 1099-B most people can just input at summary level, if you have any adjustments such as wash sales, AMD or non covered securities those are best input at detailed level to avoid adjusting sales summaries which will trigger a need to mail your 1099-B to IRS.
On one of the many other threads about this issue, someone from TT vaguely posted "Our developers are looking into import issues. Northwest Mutual and Golden Sachs import should work now." but did not mention E*Trade/Morgan specifically.
https://ttlc.intuit.com/community/taxes/discussion/re-importing-etrade-is-not-working-e-trade-from-m...
