@Innocent resident, so, I've worked with IMGs from the middle east. One has a hijab. (It feels really weird saying that in the sense that I've enjoyed working with them so much that's kinda the last thing I ever think about.) What stands out first about them is that they're amazing clinicians, supportive co-workers and compassionate with patients. I don't see them as IMGs, as they're my co-workers. For one of them, the nurses routinely tell their supervisor and the head of dept how wonderful they are. That said, they're now PGY5-6, and have fully adapted.
Whether they struggled at first, I've never actually asked. It was only much later in working with them that it came out that they were formerly refugees with foreign medical degrees. I'm sure I had assumed as much, but it wasn't really the first thing that ever came up in conversation while we were swamped with jobs. If there's been discrimination against them in some way, it hasn't affected their standing in the teams or discipline as they're both well regarded and everyone enjoys working with them. Their contributions far outweigh any discrimination that could arise from their 'identities.' (Hope that gives you a bit of hope).
I have no idea if their English is grand enough to write textbooks with, but what's key is that they are able to communicate clearly and appropriately. Their notes read like how you would expect for any doctor or resident in a Western, English speaking country.
(I work in Australia by the way, to give some context. On the side, when that Muslim ban initially happened, I remember the department head where I was rotating went "fudge, I guess we'll have to re-think going on any international conferences in the US." one of the attendings is from Sudan, not to mention 1-2 of their senior residents and fellows being originally from affected countries in the middle east. Sorry, random side story. Moving on...).
On the other hand, I've just heard of a native English speaker in another program/hospital being put on probation, for a myriad of reasons, but a few on the list include poor communication, poor English language skills and being unable to accept or understand criticism enough to improve. Native speakers too can struggle with English proficiency. It's rare that it does occur, particularly as they would have had to survive medical school. Regardless, poor English language skills is one of the reasons for the program to see this particular intern as unsafe.
Unfortunately, the medical profession is one that requires a command of the English language that is higher than average. Because you have to be a safe practitioner. You're dealing with the lives and well being of your patients. So, it matters. For instance, any text you write while at work after seeing a patient etc. is considered legal documentation. Any ward round notes are forms of communication to other staff, co-residents and other treating teams that will need them to check the progress of your patient or to action any jobs. If it's not clear to them what is going on or if there's any misunderstanding it can lead to errors. When you go to write a referral letter to another discipline - they need to understand clearly what's going on, and why their assessment is required, as they won't know your patient. When you go through informed consent with your patients you have to effectively communicate the risks and benefits to them. The list could go on. No one is saying that you have to sound like David Attenborough, but they have to feel comfortable enough to allow you to be responsible for their patients.
Try not to wallow in what you're working against with discrimination or being on probation. It's tough, I can't even imagine how hard that is to cope with, but it's something you cannot change. Or try to reserve only 5 minutes a day to allow yourself to reflect and feel bad about it, but then return to focussing on changing the things that you can control - your ability to communicate and your clinical skills.