That's unlikely - unless your BRAS/IP profile is changing - and that would only occur if your sync speed is dropping too.
More-likely it's local contention; which may be expected to be a bit higher than usual for the next couple of weeks, given Wimbledon coverage, as people at work do tend to make use of streaming servers to watch the matches.
Leo will no doubt look in more detail at your particular circumstances to see if there's anything else at play here.
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