No deduction shall be allowed under this chapter for expenses for travel as a form of education." (https://www.law.cornell.edu/uscode/text/26/274 ). But this paragraph refers to the attempt to travel for fun and being to deduct, say, if you traveled around Europe for three weeks for vacation and tried to deduct it because it was "educational" (well, it is, in a way).
However, at the beginning of Section 274, the code clearly states: (you can deduct) "An activity described in section 212 (which) shall be treated as a trade or business." Section 274 (a)(2)(B) at the link above. Section 212 is very short and most importantly says, "In the case of an individual, there shall be allowed as a deduction all the ordinary and necessary expenses paid or incurred during the taxable year—for the production or collection of income..." See https://www.law.cornell.edu/uscode/text/26/212
If you have a Schedule C business as a travel agent, and expenses for FAM trips are "ordinary and necessary" (see Section 212) in the travel agent industry (as I believe they are within limits), then I see no reason for the IRS to call them educational, unless you were unable to prove that these expenses were directly related to the production of income (or perhaps you didn't know that you needed to).
As for the reference to the Tax Cut and Jobs Act of 12/22/2017, this is referring to the following: "The 2017 TCJA eliminated the deduction for any expenses related to activities generally considered entertainment, amusement or recreation." (See https://www.irs.gov/newsroom/irs-issues-guidance-on-tax-cuts-and-jobs-act-changes-on-business-expense-deductions-for-meals-entertainment ). Again, your FAM trips, if done to further the production of income in your business, should not be considered "entertainment, amusement or recreation", but instead are "ordinary and necessary" business expenses. This is easier to argue if you are a Schedule C filer and not an employee, because the Tax Cut and Jobs Act disallowed a large number of employee business expenses starting in tax year 2018.
Now, I am answering somewhat in the dark, because I do not know which tax year was audited, I don't know what the audit letter said, I don't know if you had an office visit and what was said there - all of which might alter my response to you.
However, on the face of it, if these FAM trips are an ordinary and necessary expense for your Schedule C business (you should be able to get supporting data from your industry's trade association), then they should be deductible - at least to a large extent.
If the IRS has already made some sort of determination, you may be well advised to consult a local Enrolled Agent or CPA to represent you to the IRS in any appeal. Enrolled Agents are empowered to represent any taxpayer on any tax issue before any office of the IRS. Since they are enrolled and regulated directly by the IRS, they would likely be able to address your situation (of course, you want an EA with practical experience in audits, as not all of them do it - ask). Ditto with CPAs - they are all able to represent you, but many CPAs don't do tax (there is a lot to the world of accounting besides tax accounting) or if they do, don't do in-office audits. Again, ask.
To find a local Enrolled Agent, please go to https://taxexperts.naea.org/ . To find a local CPA, look them up in your local Yellow Pages or your state CPA registry.
Good luck.