For simplicity I will try to explain my question with a real example.
The 28th Abu Dhabi International Chess Festival - Masters was held from 2022/08/17 - 2022/08/25 and therefore the ratings changes of that event have already been updated in FIDE
GM Erigaisi was at 2689 FIDE and gained 22 elo from that. Now his FIDE shows 2725 (also after adding the olympiad rating changes that month).
Now on 2022/08/27 the Dubai Open 2022 started and it is still underway. GM Erigaisi is playing there too and on chess results it shows his starting rating as 2689 since the tournament started last month. Lets say he ended the event with +10 points according to chess results.
Now in the next month calculation will his rating be calculated such that 2725+10 or will that +10 be adjusted as if he played the tournament as a 2725 player thereby decreasing the amount of elo that will be added.
This won't be much at that level anyway since K factor is 10. But say a player with 2250 gained 150 rating points in Abu Dhabi and in Dubai gained another 100 points (as a 2250). Will his rating be 2250+150+100 = 2500?