That seems like a problem of your employer imo. If they understand software development they'll know that blockers and problems habitually crop up and should be expected and timetabled for.
Putting on pressure to get stuff done hastily or creating artificial deadlines will just make things much worse + create a load of technical debt for later. In my experience manager types who have little or no experience actualy building stuff themselves think this is a good idea, 'they must be goofing off I'll, light a fire under them!'
From the simpsons...
Hank Scorpio: I'm gonna leave everything to you. We're on a tight schedule. You
keep them motivated. [he leaves]
[his staff is busily working]
Homer: [to staff] Are you guys working?
Man 1: Yes, sir, Mr. Simpson.
Homer: Could you, um... work any harder than this?
Man 2: Sure thing, boss.
[they do]
Also relevant if your self-employed. In that case you must not be creating realistic schedules for yourself.
If I'm doing some project with a hard real deadline say, 3 months away. I'll arrange my timetable to have everything completely finished at least a week early cus I know, something or other will crop up at end end.
In conclusion perhaps scheduling/planning/timetabling issues are the route cause here.
If you arent self employed you should definitely bring this up with your employer. If they are even halfway decent they should take this very seriously.
ps. I've only been working in software for a few years now but I have a good few years of experience working as an architect (building buildings) Architecture is all about project management and stuff always goes wrong! + If you delay the project everyone sues your ass off!!