How are you observing the "loss" with DOTs? Are you just comparing an X-minute parse without using DOTs to one while using DOTs?

Due to RNG with crits in general, that's not an effective way of assessing how well the parser is picking up DOTs, unless the difference you're observing is major.

I would suggest taking both detailed parses with %crit for each ability, de-factoring the crit to isolate their base damages, and re-applying a standard crit% rate to re-create the parse equally between both. Compare those to observe what your results are between "DoTs" and "no DoTs".

Or are you eyeballing the DOT tick for individual DOTs and checking what the parser is recording them as?

That result should be pretty accurate for regular damage (but prone to RNG crits).

Edit:

Also, try ACT!