What are the potential issues when re-entering Thailand on an ED visa after traveling abroad?

My girl was pulled aside and spoke to in Thai and they wanted her to answer in Thai also asked her to write something in Thai if your going to an accredited school and you can show your learning should be ok

With an ED visa, even though it is for 1 year, you still must extend it every 90 days. If you do not have an extension done in July, and now it's August, you could actually be denied entry. Lots used falsely issued ED visas during covid, and still, up to a few months back when it was all busted, with immigration officers from 3 different provinces fired and prosecuted. The people that had problems, and refused entry back into Thailand, were the ones that didn't have all the 90 day extensions they were supposed to have. The ones that had all the correct 90 day extensions had no problems re-entering.

Very risky. The more documentation you can have with you regarding the reason you needed to leave Thailand the better.

Almost anyone with any ED in their passport even if it's from the past is facing extra scrutiny upon entering Thailand.

Leaving while on an ED can raise red flags as you have the visa/extension for the purpose of studying which you cannot do if you leave the country.

Expect to pulled out of line, asked questions about why you're in Thailand, why you left, and potentially asked questions in Thai and expected to respond in Thai.