Supporten sa att jag skulle uppdatera mobilen och försöka igen senare.

Because Swedish often marks definiteness on the noun itself.

• support = support
• supporten = the support

Here supporten most naturally means the support team, customer support, or technical support. Swedish uses the definite ending -en because the speaker is referring to a specific support service already understood from the context.

Yes. Sa is the past tense of säga, which means to say.

• säga = to say
• säger = says / is saying
• sa = said

You may also see sade as a past form. Both exist, but sa is very common in everyday Swedish.

Att here means that and introduces a subordinate clause.

So:

• Supporten sa = The support team said
• att jag skulle uppdatera mobilen... = that I should update the phone...

In English, that is often optional, and the same is true in Swedish in some contexts. But using att is very normal and clear.

Because skulle uppdatera does not mean that the update already happened. It means something like:

• should update
• was supposed to update
• was to update

In reported speech, skulle often expresses what someone said was supposed to happen or what someone told someone to do.

So Supporten sa att jag skulle uppdatera mobilen means the support team told me that I should update the phone. It does not mean I actually updated it.

Because after the modal verb skulle, Swedish uses the bare infinitive.

So:

• skulle uppdatera = should update
• not skulle att uppdatera

This is similar to English:

• should update
• not should to update

The same happens with other modal verbs such as kan, vill, måste, and ska.

No. Skulle can mean different things depending on context. Common meanings include:

• would
• should
• was supposed to
• was going to

In this sentence, skulle is best understood as should or was supposed to, because it reports advice or instructions from support.

So here it is not mainly a conditional would.

Swedish often uses the definite form where English would prefer a possessive like my.

So:

• uppdatera mobilen literally = update the phone
• but in natural English it may mean update my phone

Because it is obvious whose phone is meant, Swedish does not always need min. This is very common with things closely connected to the person or situation.

Because it is coordinated with uppdatera after skulle.

The structure is:

• jag skulle uppdatera mobilen och försöka igen senare

Both verbs depend on skulle:

• skulle uppdatera
• [skulle] försöka

The second skulle is simply left out because it would be repetitive. English does the same:

• I should update the phone and try again later

They do different jobs:

• igen = again
• senare = later

So försöka igen senare means try again later.

You need both ideas:

• igen says it is a repeated attempt
• senare says the repeated attempt should happen at a later time

Usually no, not in the same way.

• senare = later
• sedan = then / afterwards / since

In this sentence, senare is the natural choice because the meaning is at a later time.

So:

• försöka igen senare = try again later

Using sedan here would change the feel and would usually not be the standard wording for this idea.

The clause after att is a subordinate clause, and the basic order here is:

• att
• jag = subject
• skulle = finite verb
• uppdatera = infinitive
• mobilen = object

So it is:

• att jag skulle uppdatera mobilen

This looks fairly similar to English word order. A useful thing to remember is that Swedish main clauses usually follow the verb-second rule, but subordinate clauses introduced by att do not work in exactly the same way.

Yes. Swedish has borrowed many technology and service-related words from English, and support is one of them.

It is treated like a normal Swedish noun, so it can take Swedish endings:

• support
• supporten
• supportens

So even though it looks English, the grammar around it is fully Swedish.

It is mostly neutral everyday Swedish.

A few points:

• Supporten is common in everyday speech and writing.
• sa is a normal, common past-tense form.
• uppdatera mobilen sounds natural in modern Swedish.
• försöka igen senare is a very standard phrase.

So the whole sentence sounds like normal spoken or written Swedish, especially in a tech-support context.