In my experience. EAs won't take off the market u til the memorandum of sale has been produced.
To do this, they need actual evidence that the offer is proceedable via evidence of deposit, mortgage in principle and a solicitor appointed.
Serious buyers will often show EAs most of this stuff before doing viewings or at the same time and if they haven't, within 48 hours of an offer being accepted. And at this point the memorandum of sale can be produced and it marked SSTC.
Some buyers have no sense of urgency and lots in reality are not proceedable. They either lack the necessary deposit or won't get the mortgage. They are essentially time wasters. And it's understandable that people don't want to lose other potential buyers if this is the case.
So, what I think is reasonable is that buyers make an offer subject to it being removed from viewings immediately the EA has seen the paperwork...evidence of funds, details of appointed solicitor and mortgage in principle.
If a seller cannot provide these things, then to be honest they aren't proceedable. If a seller and their EA won't pull the property from the market at that point (assuming they accepted the offer because the EA had been able to fully ascertain the buyers financial position and advise the seller if they were not just proceedable but good candidates (ie short or no chain, decent equity or large deposit etc) based on evidence, then I wouldn't be prepared to continued the process.
It is a 2 way deal. Buyers need to have their ducks in a row and to be able to sow evidence very speedily. Sellers need to accept when they have a strong buyer and take it off the market.
Op, have you showed the EA all the necessary paperwork? Have you had a memorandum of sale? I suspect these things haven't happened yet. If not the best thing you can do is to get that stuff to the EA and appoint solicitor and show evidence that the survey is booked.
Go into the EA with all this stuff if you haven't already and have a conversation with them. Make clear you are proceedable and serious and that you expect the evidence to be enough to have it removed from the market.
To be honest, until the memo of sale is actually produced (and it often takes a week) you are vulnerable to other people looking and offering more. It's why it's so important to show as much documentation upfront or have it ready before you start viewings, so that when you do see the right property, you are ready to head straight to the EA with it all. It makes a massive difference in both securing a property with an offer and also helping prevent others maki g higher offers. Slowness and a lack of being fully on the ball is often a cause of people losing properties to someone else in the early stages.
Of course, you can't totally mitigate against it happening and sometimes a significant oh higher offer will appear really early on or sellers will be arse holes and holt for more.....but most will accept a good, supported offer on the advice of their EA once the EA has seen all the evidence with their own eyes.