Are federal taxes experiencing delays this year?

Indeed they are.  The IRS is seriously backlogged due to all the new tax laws and extra stimulus filings, as well as unprocessed 2019 returns left over from the COVID shutdown.  In addition, the Where's My Refund site has been erratic and unreliable.  But if TT told you that the IRS Accepted your filing for processing, then the government has it.  (Approved is a later step, but TT receives no further updates once a return is Accepted.)  Unfortunately, contacting the IRS will not speed things up.  Lots of other folks are still waiting, so please continue to be patient.  Also see:

Tax refund delay: As tax season heads into the home stretch, some taxpayers are still waiting on the IRS to finish 2019 - CBS News

The IRS is under serious stress — what does that mean for your refund? (msn.com)

What led to IRS backlog: ‘Thin workforce,’ new pandemic relief programs | Federal News Network

The IRS is sending out Stimulus #3 payments in batches, and will take a few weeks to complete them all.  This one comes to you separately (and automatically), not as part of your 2020 tax refund.  You can check the status here:

Get My Payment | Internal Revenue Service (irs.gov)