Over several days last month, online problems wiped out access to WhatsApp, Facebook, Instagram and TikTok - the most popular platforms with Guineans, more than half of whom are under 20 - while many websites were either down or working at glacial speed.
"Communications were impossible," said Nouhou Balde, founder of the online news site Guinee-Matin.
"From May 8 our readers started to complain they couldn't read our content. The overwhelming majority are in Guinea - more than 60 percent - so we've lost a lot of readership and partnerships."
The first major problems with internet connections coincided with a protest call on May 17.
The government spoke of a "breakdown" that "caused capacity restrictions."
Some media linked it to a fault in the Africa Coast to Europe (ACE) fiber-optic submarine cable system, the only one serving the country.
But the Open Observatory of Network Interference (OONI), a global NGO that monitors internet censorship, published data showing "a blockage" in Guinea between May 17-23 that specifically targeted certain platforms, not the entire network.
Another monitor, London-based NetBlocks, said there was no problem with the ACE cable and evidence pointed to "a government decision."
During the 2020 elections, the internet was completely cut off, Isik Mater, research director at Netblocks, told AFP.
"But this time, we have localized disruptions, targeting in particular the most popular platforms such as Facebook and YouTube.
"Twitter, for example, which is not widely used in Guinea, has been virtually unaffected," she continued.
NetBlocks also noted that certain internet operators in Guinea "such as Mouna and VDC Telecom have not been affected, even though they source their supplies from the same upstream location."
On May 23, private media and online outlets in the country held a one-day boycott of news over the restrictions and at the closure of two radio stations owned by the Afric Vision group.
Connections have since been largely restored, but accusations are spreading of cyber censorship, something the ruling military denies.
An influential bloggers' association, Ablogui, condemned the authorities for using "retrograde methods" that it said were linked to protests against junta leader Colonel Mamady Doumbouya. Several people died in clashes with the security forces.
The chronically unstable state has been run by the army since 2021, when President Alpha Conde, the country's first freely elected leader, was overthrown.
The junta has promised, in the face of international pressure, to restore civilian rule by the end of 2024, purportedly to give it enough time to carry out institutional reforms.
But it has arrested a number of opposition leaders and launched prosecutions against others after last year banning all demonstrations.
It has also vowed to close any media that contributes to "undermining national unity" or "stirring up (Guineans) against each other."
Restricting access to the internet is a favorite tool of repressive regimes, say watchdogs.
U.S.-based democracy watchdog Freedom House, in its 2022 World Report, found that free access to the internet had declined for the twelfth consecutive year.
The sharpest declines were recorded in Russia, Myanmar, Sudan and Libya.
In addition to infrastructure barriers, Freedom House noted that these restrictions can result from "government decisions to shut down connectivity or block specific applications."
Among African countries, Cameroon and Uganda in 2021 and Nigeria and Sierra Leone in 2022 are recent cases of blocking.