I would say being pressured to give tokens for various personal reasons. "I have a migraine, help me hit my goal in the next 15 minutes so I can get out of here," "my son needs an operation," "my car is in the shop and I need to get it fixed," etc. I am not actually opposed to helping out a model who I have built some trust with over time (though these models would very rarely if ever put me on the spot with such a request), but the problem is that you just never know if the reason is legitimate or not and it isn't really directly tied to the activity we are engaging in - and some models hit you with these things right out of the gate. It gets really awkward and I have left several rooms where I had intended to stay/continue tipping because of it.
Another one is a lack of clarity in a tip menu/prices. I am happy to either pay the model's rates or opt out if it is more than I am comfortable with, but I have had situations where the model wasn't at all clear. Example - I went to a new (to me) model, was interested in something not on the tip menu and PMed her asking about it. She says "sure, I do that, 100 tokens." Her price was a little high compared to other models and also compared to other similar items on her tip menu, but I figured why not and tip it. She doesn't do anything at first. I PMed and asked if the tip came through and her response is "oh yeah, I was waiting for you to start the private - I only do that in private." She never mentioned this in our PM exchange and had no items on her tip menu that stated they were "private only." I just told her to keep the tokens and never went back - I'm not fighting about that stuff with anyone, life is too short. I guess what I would like to see is clarity on tip menu as to what costs what and if anything must be done in a private (most models do this well) and if you are in a discussion about something, be clear about your parameters. I think disclosing something would only be done in a private is not too much to ask.
Funny, but models immediately PMing has come up a lot - it doesn't bother me at all. I chalk this up to "hate the game, not the player." Each of these models is trying to engage users (especially those who have tokens) and build a following. Sure, some models are smoother about it than others, but if the model doesn't repeatedly do it unprompted after that initial PM then I don't think anything of it. My take is that many models seem to be struggling to attract users to their rooms (at least ones that might tip) right now so I can't really begrudge assertiveness in trying to do this. Some are just awkward about it, but in many cases it seems like it could be newness to the job or a language barrier. It is easy to ignore a PM and move on IMO